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// needs Markdown.Converter.js at the moment

        (function() {

            var util = {},
                    position = {},
                    ui = {},
                    doc = window.document,
                    re = window.RegExp,
                    nav = window.navigator,
                    SETTINGS = {lineLength: 72},
            // Used to work around some browser bugs where we can't use feature testing.
            uaSniffed = {
                isIE: /msie/.test(nav.userAgent.toLowerCase()),
                isIE_5or6: /msie 6/.test(nav.userAgent.toLowerCase()) || /msie 5/.test(nav.userAgent.toLowerCase()),
                isOpera: /opera/.test(nav.userAgent.toLowerCase())
            };

            var defaultsStrings = {
                bold: "Strong <strong> Ctrl+B",
                boldexample: "strong text",
                italic: "Emphasis <em> Ctrl+I",
                italicexample: "emphasized text",
                link: "Hyperlink <a> Ctrl+L",
                linkdescription: "enter link description here",
                linkdialog: "<p><b>Insert Hyperlink</b></p><p>http://example.com/ \"optional title\"</p>",
                quote: "Blockquote <blockquote> Ctrl+Q",
                quoteexample: "Blockquote",
                code: "Code Sample <pre><code> Ctrl+K",
                codeexample: "enter code here",
                image: "Image <img> Ctrl+G",
                imagedescription: "enter image description here",
                imagedialog: "<p><b>Insert Image</b></p><p>http://example.com/images/diagram.jpg \"optional title\"<br><br>Need <a href='http://www.google.com/search?q=free+image+hosting' target='_blank'>free image hosting?</a></p>",
                olist: "Numbered List <ol> Ctrl+O",
                ulist: "Bulleted List <ul> Ctrl+U",
                litem: "List item",
                heading: "Heading <h1>/<h2> Ctrl+H",
                headingexample: "Heading",
                hr: "Horizontal Rule <hr> Ctrl+R",
                undo: "Undo - Ctrl+Z",
                redo: "Redo - Ctrl+Y",
                redomac: "Redo - Ctrl+Shift+Z",
                help: "Markdown Editing Help"
            };


            // -------------------------------------------------------------------
            //  YOUR CHANGES GO HERE
            //
            // I've tried to localize the things you are likely to change to
            // this area.
            // -------------------------------------------------------------------

            // The default text that appears in the dialog input box when entering
            // links.
            var imageDefaultText = "http://";
            var linkDefaultText = "http://";

            // -------------------------------------------------------------------
            //  END OF YOUR CHANGES
            // -------------------------------------------------------------------

            // options, if given, can have the following properties:
            //   options.helpButton = { handler: yourEventHandler }
            //   options.strings = { italicexample: "slanted text" }
            // `yourEventHandler` is the click handler for the help button.
            // If `options.helpButton` isn't given, not help button is created.
            // `options.strings` can have any or all of the same properties as
            // `defaultStrings` above, so you can just override some string displayed
            // to the user on a case-by-case basis, or translate all strings to
            // a different language.
            //
            // For backwards compatibility reasons, the `options` argument can also
            // be just the `helpButton` object, and `strings.help` can also be set via
            // `helpButton.title`. This should be considered legacy.
            //
            // The constructed editor object has the methods:
            // - getConverter() returns the markdown converter object that was passed to the constructor
            // - run() actually starts the editor; should be called after all necessary plugins are registered. Calling this more than once is a no-op.
            // - refreshPreview() forces the preview to be updated. This method is only available after run() was called.
            Markdown.Editor = function(markdownConverter, idPostfix, options) {

                options = options || {};

                if(typeof options.handler === "function") { //backwards compatible behavior
                    options = {helpButton: options};
                }
                options.strings = options.strings || {};
                if(options.helpButton) {
                    options.strings.help = options.strings.help || options.helpButton.title;
                }
                var getString = function(identifier) {
                    return options.strings[identifier] || defaultsStrings[identifier];
                }

                idPostfix = idPostfix || "";

                var hooks = this.hooks = new Markdown.HookCollection();
                hooks.addNoop("onPreviewRefresh");       // called with no arguments after the preview has been refreshed
                hooks.addNoop("postBlockquoteCreation"); // called with the user's selection *after* the blockquote was created; should return the actual to-be-inserted text
                hooks.addFalse("insertImageDialog");     /* called with one parameter: a callback to be called with the URL of the image. If the application creates
                 * its own image insertion dialog, this hook should return true, and the callback should be called with the chosen
                 * image url (or null if the user cancelled). If this hook returns false, the default dialog will be used.
                 */

                this.getConverter = function() {
                    return markdownConverter;
                }

                var that = this,
                        panels;

                this.run = function() {
                    if(panels)
                        return; // already initialized

                    panels = new PanelCollection(idPostfix);
                    var commandManager = new CommandManager(hooks, getString, markdownConverter);
                    var previewManager = new PreviewManager(markdownConverter, panels, function() {
                        hooks.onPreviewRefresh();
                    });
                    var undoManager, uiManager;

                    if(!/\?noundo/.test(doc.location.href)) {
                        undoManager = new UndoManager(function() {
                            previewManager.refresh();
                            if(uiManager) // not available on the first call
                                uiManager.setUndoRedoButtonStates();
                        }, panels);
                        this.textOperation = function(f) {
                            undoManager.setCommandMode();
                            f();
                            that.refreshPreview();
                        }
                    }

                    uiManager = new UIManager(idPostfix, panels, undoManager, previewManager, commandManager, options.helpButton, getString);
                    uiManager.setUndoRedoButtonStates();

                    var forceRefresh = that.refreshPreview = function() {
                        previewManager.refresh(true);
                    };

                    forceRefresh();
                };

            }

            // before: contains all the text in the input box BEFORE the selection.
            // after: contains all the text in the input box AFTER the selection.
            function Chunks() { }

            // startRegex: a regular expression to find the start tag
            // endRegex: a regular expresssion to find the end tag
            Chunks.prototype.findTags = function(startRegex, endRegex) {

                var chunkObj = this;
                var regex;

                if(startRegex) {

                    regex = util.extendRegExp(startRegex, "", "$");

                    this.before = this.before.replace(regex,
                            function(match) {
                                chunkObj.startTag = chunkObj.startTag + match;
                                return "";
                            });

                    regex = util.extendRegExp(startRegex, "^", "");

                    this.selection = this.selection.replace(regex,
                            function(match) {
                                chunkObj.startTag = chunkObj.startTag + match;
                                return "";
                            });
                }

                if(endRegex) {

                    regex = util.extendRegExp(endRegex, "", "$");

                    this.selection = this.selection.replace(regex,
                            function(match) {
                                chunkObj.endTag = match + chunkObj.endTag;
                                return "";
                            });

                    regex = util.extendRegExp(endRegex, "^", "");

                    this.after = this.after.replace(regex,
                            function(match) {
                                chunkObj.endTag = match + chunkObj.endTag;
                                return "";
                            });
                }
            };

            // If remove is false, the whitespace is transferred
            // to the before/after regions.
            //
            // If remove is true, the whitespace disappears.
            Chunks.prototype.trimWhitespace = function(remove) {
                var beforeReplacer, afterReplacer, that = this;
                if(remove) {
                    beforeReplacer = afterReplacer = "";
                } else {
                    beforeReplacer = function(s) {
                        that.before += s;
                        return "";
                    }
                    afterReplacer = function(s) {
                        that.after = s + that.after;
                        return "";
                    }
                }

                this.selection = this.selection.replace(/^(\s*)/, beforeReplacer).replace(/(\s*)$/, afterReplacer);
            };


            Chunks.prototype.skipLines = function(nLinesBefore, nLinesAfter, findExtraNewlines) {

                if(nLinesBefore === undefined) {
                    nLinesBefore = 1;
                }

                if(nLinesAfter === undefined) {
                    nLinesAfter = 1;
                }

                nLinesBefore++;
                nLinesAfter++;

                var regexText;
                var replacementText;

                // chrome bug ... documented at: http://meta.stackexchange.com/questions/63307/blockquote-glitch-in-editor-in-chrome-6-and-7/65985#65985
                if(navigator.userAgent.match(/Chrome/)) {
                    "X".match(/()./);
                }

                this.selection = this.selection.replace(/(^\n*)/, "");

                this.startTag = this.startTag + re.$1;

                this.selection = this.selection.replace(/(\n*$)/, "");
                this.endTag = this.endTag + re.$1;
                this.startTag = this.startTag.replace(/(^\n*)/, "");
                this.before = this.before + re.$1;
                this.endTag = this.endTag.replace(/(\n*$)/, "");
                this.after = this.after + re.$1;

                if(this.before) {

                    regexText = replacementText = "";

                    while(nLinesBefore--) {
                        regexText += "\\n?";
                        replacementText += "\n";
                    }

                    if(findExtraNewlines) {
                        regexText = "\\n*";
                    }
                    this.before = this.before.replace(new re(regexText + "$", ""), replacementText);
                }

                if(this.after) {

                    regexText = replacementText = "";

                    while(nLinesAfter--) {
                        regexText += "\\n?";
                        replacementText += "\n";
                    }
                    if(findExtraNewlines) {
                        regexText = "\\n*";
                    }

                    this.after = this.after.replace(new re(regexText, ""), replacementText);
                }
            };

            // end of Chunks

            // A collection of the important regions on the page.
            // Cached so we don't have to keep traversing the DOM.
            // Also holds ieCachedRange and ieCachedScrollTop, where necessary; working around
            // this issue:
            // Internet explorer has problems with CSS sprite buttons that use HTML
            // lists.  When you click on the background image "button", IE will
            // select the non-existent link text and discard the selection in the
            // textarea.  The solution to this is to cache the textarea selection
            // on the button's mousedown event and set a flag.  In the part of the
            // code where we need to grab the selection, we check for the flag
            // and, if it's set, use the cached area instead of querying the
            // textarea.
            //
            // This ONLY affects Internet Explorer (tested on versions 6, 7
            // and 8) and ONLY on button clicks.  Keyboard shortcuts work
            // normally since the focus never leaves the textarea.
            function PanelCollection(postfix) {
                this.buttonBar = doc.getElementById("wmd-button-bar" + postfix);
                this.preview = doc.getElementById("wmd-preview" + postfix);
                this.input = doc.getElementById("wmd-input" + postfix);
            }
            ;

            // Returns true if the DOM element is visible, false if it's hidden.
            // Checks if display is anything other than none.
            util.isVisible = function(elem) {

                if(window.getComputedStyle) {
                    // Most browsers
                    return window.getComputedStyle(elem, null).getPropertyValue("display") !== "none";
                } else if(elem.currentStyle) {
                    // IE
                    return elem.currentStyle["display"] !== "none";
                }
            };


            // Adds a listener callback to a DOM element which is fired on a specified
            // event.
            util.addEvent = function(elem, event, listener) {
                if(elem.attachEvent) {
                    // IE only.  The "on" is mandatory.
                    elem.attachEvent("on" + event, listener);
                } else {
                    // Other browsers.
                    elem.addEventListener(event, listener, false);
                }
            };


            // Removes a listener callback from a DOM element which is fired on a specified
            // event.
            util.removeEvent = function(elem, event, listener) {
                if(elem.detachEvent) {
                    // IE only.  The "on" is mandatory.
                    elem.detachEvent("on" + event, listener);
                } else {
                    // Other browsers.
                    elem.removeEventListener(event, listener, false);
                }
            };

            // Converts \r\n and \r to \n.
            util.fixEolChars = function(text) {
                text = text.replace(/\r\n/g, "\n");
                text = text.replace(/\r/g, "\n");
                return text;
            };

            // Extends a regular expression.  Returns a new RegExp
            // using pre + regex + post as the expression.
            // Used in a few functions where we have a base
            // expression and we want to pre- or append some
            // conditions to it (e.g. adding "$" to the end).
            // The flags are unchanged.
            //
            // regex is a RegExp, pre and post are strings.
            util.extendRegExp = function(regex, pre, post) {

                if(pre === null || pre === undefined) {
                    pre = "";
                }
                if(post === null || post === undefined) {
                    post = "";
                }

                var pattern = regex.toString();
                var flags;

                // Replace the flags with empty space and store them.
                pattern = pattern.replace(/\/([gim]*)$/, function(wholeMatch, flagsPart) {
                    flags = flagsPart;
                    return "";
                });

                // Remove the slash delimiters on the regular expression.
                pattern = pattern.replace(/(^\/|\/$)/g, "");
                pattern = pre + pattern + post;

                return new re(pattern, flags);
            }

            // UNFINISHED
            // The assignment in the while loop makes jslint cranky.
            // I'll change it to a better loop later.
            position.getTop = function(elem, isInner) {
                var result = elem.offsetTop;
                if(!isInner) {
                    while(elem = elem.offsetParent) {
                        result += elem.offsetTop;
                    }
                }
                return result;
            };

            position.getHeight = function(elem) {
                return elem.offsetHeight || elem.scrollHeight;
            };

            position.getWidth = function(elem) {
                return elem.offsetWidth || elem.scrollWidth;
            };

            position.getPageSize = function() {

                var scrollWidth, scrollHeight;
                var innerWidth, innerHeight;

                // It's not very clear which blocks work with which browsers.
                if(self.innerHeight && self.scrollMaxY) {
                    scrollWidth = doc.body.scrollWidth;
                    scrollHeight = self.innerHeight + self.scrollMaxY;
                } else if(doc.body.scrollHeight > doc.body.offsetHeight) {
                    scrollWidth = doc.body.scrollWidth;
                    scrollHeight = doc.body.scrollHeight;
                } else {
                    scrollWidth = doc.body.offsetWidth;
                    scrollHeight = doc.body.offsetHeight;
                }

                if(self.innerHeight) {
                    // Non-IE browser
                    innerWidth = self.innerWidth;
                    innerHeight = self.innerHeight;
                } else if(doc.documentElement && doc.documentElement.clientHeight) {
                    // Some versions of IE (IE 6 w/ a DOCTYPE declaration)
                    innerWidth = doc.documentElement.clientWidth;
                    innerHeight = doc.documentElement.clientHeight;
                } else if(doc.body) {
                    // Other versions of IE
                    innerWidth = doc.body.clientWidth;
                    innerHeight = doc.body.clientHeight;
                }

                var maxWidth = Math.max(scrollWidth, innerWidth);
                var maxHeight = Math.max(scrollHeight, innerHeight);
                return [maxWidth, maxHeight, innerWidth, innerHeight];
            };

            // Handles pushing and popping TextareaStates for undo/redo commands.
            // I should rename the stack variables to list.
            function UndoManager(callback, panels) {

                var undoObj = this;
                var undoStack = []; // A stack of undo states
                var stackPtr = 0; // The index of the current state
                var mode = "none";
                var lastState; // The last state
                var timer; // The setTimeout handle for cancelling the timer
                var inputStateObj;

                // Set the mode for later logic steps.
                var setMode = function(newMode, noSave) {
                    if(mode != newMode) {
                        mode = newMode;
                        if(!noSave) {
                            saveState();
                        }
                    }

                    if(!uaSniffed.isIE || mode != "moving") {
                        timer = setTimeout(refreshState, 1);
                    } else {
                        inputStateObj = null;
                    }
                };

                var refreshState = function(isInitialState) {
                    inputStateObj = new ContenteditableState(panels, isInitialState);
                    timer = undefined;
                };

                this.setCommandMode = function() {
                    mode = "command";
                    saveState();
                    timer = setTimeout(refreshState, 0);
                };

                this.canUndo = function() {
                    return stackPtr > 1;
                };

                this.canRedo = function() {
                    if(undoStack[stackPtr + 1]) {
                        return true;
                    }
                    return false;
                };

                // Removes the last state and restores it.
                this.undo = function() {

                    if(undoObj.canUndo()) {
                        if(lastState) {
                            // What about setting state -1 to null or checking for undefined?
                            lastState.restore();
                            lastState = null;
                        } else {
                            undoStack[stackPtr] = new ContenteditableState(panels);
                            undoStack[--stackPtr].restore();

                            if(callback) {
                                callback();
                            }
                        }
                    }

                    mode = "none";
                    panels.input.focus();
                    refreshState();
                };

                // Redo an action.
                this.redo = function() {

                    if(undoObj.canRedo()) {

                        undoStack[++stackPtr].restore();

                        if(callback) {
                            callback();
                        }
                    }

                    mode = "none";
                    panels.input.focus();
                    refreshState();
                };

                // Push the input area state to the stack.
                var saveState = function() {
                    var currState = inputStateObj || new ContenteditableState(panels);

                    if(!currState) {
                        return false;
                    }
                    if(mode == "moving") {
                        if(!lastState) {
                            lastState = currState;
                        }
                        return;
                    }
                    if(lastState) {
                        if(undoStack[stackPtr - 1].text != lastState.text) {
                            undoStack[stackPtr++] = lastState;
                        }
                        lastState = null;
                    }
                    undoStack[stackPtr++] = currState;
                    undoStack[stackPtr + 1] = null;
                    if(callback) {
                        callback();
                    }
                };

                var handleCtrlYZ = function(event) {

                    var handled = false;

                    if((event.ctrlKey || event.metaKey) && !event.altKey) {

                        // IE and Opera do not support charCode.
                        var keyCode = event.charCode || event.keyCode;
                        var keyCodeChar = String.fromCharCode(keyCode);

                        switch(keyCodeChar.toLowerCase()) {

                            case "y":
                                undoObj.redo();
                                handled = true;
                                break;

                            case "z":
                                if(!event.shiftKey) {
                                    undoObj.undo();
                                } else {
                                    undoObj.redo();
                                }
                                handled = true;
                                break;
                        }
                    }

                    if(handled) {
                        if(event.preventDefault) {
                            event.preventDefault();
                        }
                        if(window.event) {
                            window.event.returnValue = false;
                        }
                        return;
                    }
                };

                // Set the mode depending on what is going on in the input area.
                var handleModeChange = function(event) {

                    if(!event.ctrlKey && !event.metaKey) {

                        var keyCode = event.keyCode;

                        if((keyCode >= 33 && keyCode <= 40) || (keyCode >= 63232 && keyCode <= 63235)) {
                            // 33 - 40: page up/dn and arrow keys
                            // 63232 - 63235: page up/dn and arrow keys on safari
                            setMode("moving");
                        } else if(keyCode == 8 || keyCode == 46 || keyCode == 127) {
                            // 8: backspace
                            // 46: delete
                            // 127: delete
                            setMode("deleting");
                        } else if(keyCode == 13) {
                            // 13: Enter
                            setMode("newlines");
                        } else if(keyCode == 27) {
                            // 27: escape
                            setMode("escape");
                        } else if((keyCode < 16 || keyCode > 20) && keyCode != 91) {
                            // 16-20 are shift, etc.
                            // 91: left window key
                            // I think this might be a little messed up since there are
                            // a lot of nonprinting keys above 20.
                            setMode("typing");
                        }
                    }
                };

                var setEventHandlers = function() {
                    util.addEvent(panels.input, "keypress", function(event) {
                        // keyCode 89: y
                        // keyCode 90: z
                        if((event.ctrlKey || event.metaKey) && !event.altKey && (event.keyCode == 89 || event.keyCode == 90)) {
                            event.preventDefault();
                        }
                    });

                    util.addEvent(panels.input, "focusout", function(event) {

                        var selection = window.getSelection();
                        $(panels.input).data('selection', {
                            start: {
                                node: selection.anchorNode,
                                offset: selection.anchorOffset
                            },
                            end: {
                                node: selection.focusNode,
                                offset: selection.focusOffset,
                            }
                        });
                    });

                    var handlePaste = function() {
                        if(uaSniffed.isIE || (inputStateObj && inputStateObj.text != panels.input.value)) {
                            if(timer == undefined) {
                                mode = "paste";
                                saveState();
                                refreshState();
                            }
                        }
                    };

                    util.addEvent(panels.input, "keydown", handleCtrlYZ);
                    util.addEvent(panels.input, "keydown", handleModeChange);
                    util.addEvent(panels.input, "mousedown", function() {
                        setMode("moving");
                    });

                    panels.input.onpaste = handlePaste;
                    panels.input.ondrop = handlePaste;
                };

                var init = function() {
                    setEventHandlers();
                    refreshState(true);
                    saveState();
                };

                init();
            }

            // end of UndoManager

            // The input textarea state/contents.
            // This is used to implement undo/redo by the undo manager.
            function TextareaState(panels, isInitialState) {

                // Aliases
                var stateObj = this;
                var inputArea = panels.input;
                this.init = function() {
                    if(!util.isVisible(inputArea)) {
                        return;
                    }
                    if(!isInitialState && doc.activeElement && doc.activeElement !== inputArea) { // this happens when tabbing out of the input box
                        return;
                    }

                    this.setInputAreaSelectionStartEnd();
                    this.scrollTop = inputArea.scrollTop;
                    if(!this.text && inputArea.selectionStart || inputArea.selectionStart === 0) {
                        this.text = inputArea.value;
                    }

                }

                // Sets the selected text in the input box after we've performed an
                // operation.
                this.setInputAreaSelection = function() {

                    if(!util.isVisible(inputArea)) {
                        return;
                    }

                    if(inputArea.selectionStart !== undefined && !uaSniffed.isOpera) {

                        inputArea.focus();
                        inputArea.selectionStart = stateObj.start;
                        inputArea.selectionEnd = stateObj.end;
                        inputArea.scrollTop = stateObj.scrollTop;
                    } else if(doc.selection) {

                        if(doc.activeElement && doc.activeElement !== inputArea) {
                            return;
                        }

                        inputArea.focus();
                        var range = inputArea.createTextRange();
                        range.moveStart("character", -inputArea.value.length);
                        range.moveEnd("character", -inputArea.value.length);
                        range.moveEnd("character", stateObj.end);
                        range.moveStart("character", stateObj.start);
                        range.select();
                    }
                };

                this.setInputAreaSelectionStartEnd = function() {

                    if(!panels.ieCachedRange && (inputArea.selectionStart || inputArea.selectionStart === 0)) {

                        stateObj.start = inputArea.selectionStart;
                        stateObj.end = inputArea.selectionEnd;
                    } else if(doc.selection) {

                        stateObj.text = util.fixEolChars(inputArea.value);

                        // IE loses the selection in the textarea when buttons are
                        // clicked.  On IE we cache the selection. Here, if something is cached,
                        // we take it.
                        var range = panels.ieCachedRange || doc.selection.createRange();

                        var fixedRange = util.fixEolChars(range.text);
                        var marker = "\x07";
                        var markedRange = marker + fixedRange + marker;
                        range.text = markedRange;
                        var inputText = util.fixEolChars(inputArea.value);

                        range.moveStart("character", -markedRange.length);
                        range.text = fixedRange;

                        stateObj.start = inputText.indexOf(marker);
                        stateObj.end = inputText.lastIndexOf(marker) - marker.length;

                        var len = stateObj.text.length - util.fixEolChars(inputArea.value).length;

                        if(len) {
                            range.moveStart("character", -fixedRange.length);
                            while(len--) {
                                fixedRange += "\n";
                                stateObj.end += 1;
                            }
                            range.text = fixedRange;
                        }

                        if(panels.ieCachedRange)
                            stateObj.scrollTop = panels.ieCachedScrollTop; // this is set alongside with ieCachedRange

                        panels.ieCachedRange = null;

                        this.setInputAreaSelection();
                    }
                };

                // Restore this state into the input area.
                this.restore = function() {

                    if(stateObj.text != undefined && stateObj.text != inputArea.value) {
                        inputArea.value = stateObj.text;
                    }
                    this.setInputAreaSelection();
                    inputArea.scrollTop = stateObj.scrollTop;
                };

                // Gets a collection of HTML chunks from the inptut textarea.
                this.getChunks = function() {

                    var chunk = new Chunks();
                    chunk.before = util.fixEolChars(stateObj.text.substring(0, stateObj.start));
                    chunk.startTag = "";
                    chunk.selection = util.fixEolChars(stateObj.text.substring(stateObj.start, stateObj.end));
                    chunk.endTag = "";
                    chunk.after = util.fixEolChars(stateObj.text.substring(stateObj.end));
                    chunk.scrollTop = stateObj.scrollTop;

                    return chunk;
                };

                // Sets the TextareaState properties given a chunk of markdown.
                this.setChunks = function(chunk) {

                    chunk.before = chunk.before + chunk.startTag;
                    chunk.after = chunk.endTag + chunk.after;

                    this.start = chunk.before.length;
                    this.end = chunk.before.length + chunk.selection.length;
                    this.text = chunk.before + chunk.selection + chunk.after;
                    this.scrollTop = chunk.scrollTop;
                };
                this.init();
            }
            ;

            function ContenteditableState(panels, isInitialState) {

                // Aliases
                var stateObj = this;
                var inputArea = panels.input;

                this.init = function() {
                    if(!util.isVisible(inputArea)) {
                        return;
                    }
                    if(!isInitialState && doc.activeElement && doc.activeElement !== inputArea) { // this happens when tabbing out of the input box
                        return;
                    }

                    this.setInputAreaSelectionStartEnd();
                    this.scrollTop = inputArea.scrollTop;
                    if(!this.text && inputArea.selectionStart || inputArea.selectionStart === 0) {
                        this.text = inputArea.value;
                    }

                }

                // Sets the selected text in the input box after we've performed an
                // operation.
                this.setInputAreaSelection = function() {

                    if(!util.isVisible(inputArea)) {
                        return;
                    }

                    if(inputArea.selectionStart !== undefined && !uaSniffed.isOpera) {

                        inputArea.focus();
                        inputArea.selectionStart = stateObj.start;
                        inputArea.selectionEnd = stateObj.end;
                        inputArea.scrollTop = stateObj.scrollTop;
                    } else if(doc.selection) {

                        if(doc.activeElement && doc.activeElement !== inputArea) {
                            return;
                        }

                        inputArea.focus();
                        var range = inputArea.createTextRange();
                        range.moveStart("character", -inputArea.value.length);
                        range.moveEnd("character", -inputArea.value.length);
                        range.moveEnd("character", stateObj.end);
                        range.moveStart("character", stateObj.start);
                        range.select();
                    }
                };

                this.setInputAreaSelectionStartEnd = function() {
                    console.log($(panels.input).data('selection'));
                    this.selection = $(panels.input).data('selection');

                    return;


                    if(!panels.ieCachedRange && (inputArea.selectionStart || inputArea.selectionStart === 0)) {

                        stateObj.start = inputArea.selectionStart;
                        stateObj.end = inputArea.selectionEnd;
                    } else if(doc.selection) {
                        stateObj.text = util.fixEolChars(inputArea.value);

                        // IE loses the selection in the textarea when buttons are
                        // clicked.  On IE we cache the selection. Here, if something is cached,
                        // we take it.
                        var range = panels.ieCachedRange || doc.selection.createRange();

                        var fixedRange = util.fixEolChars(range.text);
                        var marker = "\x07";
                        var markedRange = marker + fixedRange + marker;
                        range.text = markedRange;
                        var inputText = util.fixEolChars(inputArea.value);

                        range.moveStart("character", -markedRange.length);
                        range.text = fixedRange;

                        stateObj.start = inputText.indexOf(marker);
                        stateObj.end = inputText.lastIndexOf(marker) - marker.length;

                        var len = stateObj.text.length - util.fixEolChars(inputArea.value).length;

                        if(len) {
                            range.moveStart("character", -fixedRange.length);
                            while(len--) {
                                fixedRange += "\n";
                                stateObj.end += 1;
                            }
                            range.text = fixedRange;
                        }

                        if(panels.ieCachedRange)
                            stateObj.scrollTop = panels.ieCachedScrollTop; // this is set alongside with ieCachedRange

                        panels.ieCachedRange = null;

                        this.setInputAreaSelection();
                    }
                };

                // Restore this state into the input area.
                this.restore = function() {

                    if(stateObj.text != undefined && stateObj.text != inputArea.value) {
                        inputArea.value = stateObj.text;
                    }
                    this.setInputAreaSelection();
                    inputArea.scrollTop = stateObj.scrollTop;
                };

                // Gets a collection of HTML chunks from the inptut textarea.
                this.getChunks = function() {

                    var chunk = new Chunks();
                    chunk.before = util.fixEolChars(stateObj.text.substring(0, stateObj.start));
                    chunk.startTag = "";
                    chunk.selection = util.fixEolChars(stateObj.text.substring(stateObj.start, stateObj.end));
                    chunk.endTag = "";
                    chunk.after = util.fixEolChars(stateObj.text.substring(stateObj.end));
                    chunk.scrollTop = stateObj.scrollTop;

                    return chunk;
                };

                // Sets the TextareaState properties given a chunk of markdown.
                this.setChunks = function(chunk) {

                    chunk.before = chunk.before + chunk.startTag;
                    chunk.after = chunk.endTag + chunk.after;

                    this.start = chunk.before.length;
                    this.end = chunk.before.length + chunk.selection.length;
                    this.text = chunk.before + chunk.selection + chunk.after;
                    this.scrollTop = chunk.scrollTop;
                };
                this.init();
            }
            ;

            function PreviewManager(converter, panels, previewRefreshCallback) {

                var managerObj = this;
                var timeout;
                var elapsedTime;
                var oldInputText;
                var maxDelay = 3000;
                var startType = "delayed"; // The other legal value is "manual"

                // Adds event listeners to elements
                var setupEvents = function(inputElem, listener) {

                    util.addEvent(inputElem, "input", listener);
                    inputElem.onpaste = listener;
                    inputElem.ondrop = listener;

                    util.addEvent(inputElem, "keypress", listener);
                    util.addEvent(inputElem, "keydown", listener);
                };

                var getDocScrollTop = function() {

                    var result = 0;

                    if(window.innerHeight) {
                        result = window.pageYOffset;
                    } else
                    if(doc.documentElement && doc.documentElement.scrollTop) {
                        result = doc.documentElement.scrollTop;
                    } else
                    if(doc.body) {
                        result = doc.body.scrollTop;
                    }

                    return result;
                };

                var makePreviewHtml = function() {

                    // If there is no registered preview panel
                    // there is nothing to do.
                    if(!panels.preview)
                        return;


                    var text = panels.input.value;
                    if(text && text == oldInputText) {
                        return; // Input text hasn't changed.
                    } else {
                        oldInputText = text;
                    }

                    var prevTime = new Date().getTime();

                    text = converter.makeHtml(text);

                    // Calculate the processing time of the HTML creation.
                    // It's used as the delay time in the event listener.
                    var currTime = new Date().getTime();
                    elapsedTime = currTime - prevTime;

                    pushPreviewHtml(text);
                };

                // setTimeout is already used.  Used as an event listener.
                var applyTimeout = function() {

                    if(timeout) {
                        clearTimeout(timeout);
                        timeout = undefined;
                    }

                    if(startType !== "manual") {

                        var delay = 0;

                        if(startType === "delayed") {
                            delay = elapsedTime;
                        }

                        if(delay > maxDelay) {
                            delay = maxDelay;
                        }
                        timeout = setTimeout(makePreviewHtml, delay);
                    }
                };

                var getScaleFactor = function(panel) {
                    if(panel.scrollHeight <= panel.clientHeight) {
                        return 1;
                    }
                    return panel.scrollTop / (panel.scrollHeight - panel.clientHeight);
                };

                var setPanelScrollTops = function() {
                    if(panels.preview) {
                        panels.preview.scrollTop = (panels.preview.scrollHeight - panels.preview.clientHeight) * getScaleFactor(panels.preview);
                    }
                };

                this.refresh = function(requiresRefresh) {

                    if(requiresRefresh) {
                        oldInputText = "";
                        makePreviewHtml();
                    } else {
                        applyTimeout();
                    }
                };

                this.processingTime = function() {
                    return elapsedTime;
                };

                var isFirstTimeFilled = true;

                // IE doesn't let you use innerHTML if the element is contained somewhere in a table
                // (which is the case for inline editing) -- in that case, detach the element, set the
                // value, and reattach. Yes, that *is* ridiculous.
                var ieSafePreviewSet = function(text) {
                    var preview = panels.preview;
                    var parent = preview.parentNode;
                    var sibling = preview.nextSibling;
                    parent.removeChild(preview);
                    preview.innerHTML = text;
                    if(!sibling)
                        parent.appendChild(preview);
                    else
                        parent.insertBefore(preview, sibling);
                }

                var nonSuckyBrowserPreviewSet = function(text) {
                    panels.preview.innerHTML = text;
                }

                var previewSetter;

                var previewSet = function(text) {
                    if(previewSetter)
                        return previewSetter(text);

                    try {
                        nonSuckyBrowserPreviewSet(text);
                        previewSetter = nonSuckyBrowserPreviewSet;
                    } catch(e) {
                        previewSetter = ieSafePreviewSet;
                        previewSetter(text);
                    }
                };

                var pushPreviewHtml = function(text) {

                    var emptyTop = position.getTop(panels.input) - getDocScrollTop();

                    if(panels.preview) {
                        previewSet(text);
                        previewRefreshCallback();
                    }

                    setPanelScrollTops();

                    if(isFirstTimeFilled) {
                        isFirstTimeFilled = false;
                        return;
                    }

                    var fullTop = position.getTop(panels.input) - getDocScrollTop();

                    if(uaSniffed.isIE) {
                        setTimeout(function() {
                            window.scrollBy(0, fullTop - emptyTop);
                        }, 0);
                    } else {
                        window.scrollBy(0, fullTop - emptyTop);
                    }
                };

                var init = function() {

                    setupEvents(panels.input, applyTimeout);
                    makePreviewHtml();

                    if(panels.preview) {
                        panels.preview.scrollTop = 0;
                    }
                };

                init();
            }
            ;

            // Creates the background behind the hyperlink text entry box.
            // And download dialog
            // Most of this has been moved to CSS but the div creation and
            // browser-specific hacks remain here.
            ui.createBackground = function() {

                var background = doc.createElement("div"),
                        style = background.style;

                background.className = "wmd-prompt-background";

                style.position = "absolute";
                style.top = "0";

                style.zIndex = "1000";

                if(uaSniffed.isIE) {
                    style.filter = "alpha(opacity=50)";
                } else {
                    style.opacity = "0.5";
                }

                var pageSize = position.getPageSize();
                style.height = pageSize[1] + "px";

                if(uaSniffed.isIE) {
                    style.left = doc.documentElement.scrollLeft;
                    style.width = doc.documentElement.clientWidth;
                } else {
                    style.left = "0";
                    style.width = "100%";
                }

                doc.body.appendChild(background);
                return background;
            };

            // This simulates a modal dialog box and asks for the URL when you
            // click the hyperlink or image buttons.
            //
            // text: The html for the input box.
            // defaultInputText: The default value that appears in the input box.
            // callback: The function which is executed when the prompt is dismissed, either via OK or Cancel.
            //      It receives a single argument; either the entered text (if OK was chosen) or null (if Cancel
            //      was chosen).
            ui.prompt = function(text, defaultInputText, callback) {

                // These variables need to be declared at this level since they are used
                // in multiple functions.
                var dialog;         // The dialog box.
                var input;         // The text box where you enter the hyperlink.


                if(defaultInputText === undefined) {
                    defaultInputText = "";
                }

                // Used as a keydown event handler. Esc dismisses the prompt.
                // Key code 27 is ESC.
                var checkEscape = function(key) {
                    var code = (key.charCode || key.keyCode);
                    if(code === 27) {
                        if(key.stopPropagation)
                            key.stopPropagation();
                        close(true);
                        return false;
                    }
                };

                // Dismisses the hyperlink input box.
                // isCancel is true if we don't care about the input text.
                // isCancel is false if we are going to keep the text.
                var close = function(isCancel) {
                    util.removeEvent(doc.body, "keyup", checkEscape);
                    var text = input.value;

                    if(isCancel) {
                        text = null;
                    } else {
                        // Fixes common pasting errors.
                        text = text.replace(/^http:\/\/(https?|ftp):\/\//, '$1://');
                        if(!/^(?:https?|ftp):\/\//.test(text))
                            text = 'http://' + text;
                    }

                    dialog.parentNode.removeChild(dialog);

                    callback(text);
                    return false;
                };



                // Create the text input box form/window.
                var createDialog = function() {

                    // The main dialog box.
                    dialog = doc.createElement("div");
                    dialog.className = "wmd-prompt-dialog";
                    dialog.style.padding = "10px;";
                    dialog.style.position = "fixed";
                    dialog.style.width = "400px";
                    dialog.style.zIndex = "1001";

                    // The dialog text.
                    var question = doc.createElement("div");
                    question.innerHTML = text;
                    question.style.padding = "5px";
                    dialog.appendChild(question);

                    // The web form container for the text box and buttons.
                    var form = doc.createElement("form"),
                            style = form.style;
                    form.onsubmit = function() {
                        return close(false);
                    };
                    style.padding = "0";
                    style.margin = "0";
                    style.cssFloat = "left";
                    style.width = "100%";
                    style.textAlign = "center";
                    style.position = "relative";
                    dialog.appendChild(form);

                    // The input text box
                    input = doc.createElement("input");
                    input.type = "text";
                    input.value = defaultInputText;
                    style = input.style;
                    style.display = "block";
                    style.width = "80%";
                    style.marginLeft = style.marginRight = "auto";
                    form.appendChild(input);

                    // The ok button
                    var okButton = doc.createElement("input");
                    okButton.type = "button";
                    okButton.onclick = function() {
                        return close(false);
                    };
                    okButton.value = "OK";
                    style = okButton.style;
                    style.margin = "10px";
                    style.display = "inline";
                    style.width = "7em";


                    // The cancel button
                    var cancelButton = doc.createElement("input");
                    cancelButton.type = "button";
                    cancelButton.onclick = function() {
                        return close(true);
                    };
                    cancelButton.value = "Cancel";
                    style = cancelButton.style;
                    style.margin = "10px";
                    style.display = "inline";
                    style.width = "7em";

                    form.appendChild(okButton);
                    form.appendChild(cancelButton);

                    util.addEvent(doc.body, "keyup", checkEscape);
                    dialog.style.top = "50%";
                    dialog.style.left = "50%";
                    dialog.style.display = "block";
                    if(uaSniffed.isIE_5or6) {
                        dialog.style.position = "absolute";
                        dialog.style.top = doc.documentElement.scrollTop + 200 + "px";
                        dialog.style.left = "50%";
                    }
                    doc.body.appendChild(dialog);

                    // This has to be done AFTER adding the dialog to the form if you
                    // want it to be centered.
                    dialog.style.marginTop = -(position.getHeight(dialog) / 2) + "px";
                    dialog.style.marginLeft = -(position.getWidth(dialog) / 2) + "px";

                };

                // Why is this in a zero-length timeout?
                // Is it working around a browser bug?
                setTimeout(function() {

                    createDialog();

                    var defTextLen = defaultInputText.length;
                    if(input.selectionStart !== undefined) {
                        input.selectionStart = 0;
                        input.selectionEnd = defTextLen;
                    } else if(input.createTextRange) {
                        var range = input.createTextRange();
                        range.collapse(false);
                        range.moveStart("character", -defTextLen);
                        range.moveEnd("character", defTextLen);
                        range.select();
                    }

                    input.focus();
                }, 0);
            };

            function UIManager(postfix, panels, undoManager, previewManager, commandManager, helpOptions, getString) {

                var inputBox = panels.input,
                        buttons = {}; // buttons.undo, buttons.link, etc. The actual DOM elements.

                makeSpritedButtonRow();

                var keyEvent = "keydown";
                if(uaSniffed.isOpera) {
                    keyEvent = "keypress";
                }

                util.addEvent(inputBox, keyEvent, function(key) {

                    // Check to see if we have a button key and, if so execute the callback.
                    if((key.ctrlKey || key.metaKey) && !key.altKey && !key.shiftKey) {

                        var keyCode = key.charCode || key.keyCode;
                        var keyCodeStr = String.fromCharCode(keyCode).toLowerCase();

                        switch(keyCodeStr) {
                            case "b":
                                doClick(buttons.bold);
                                break;
                            case "i":
                                doClick(buttons.italic);
                                break;
                            case "l":
                                doClick(buttons.link);
                                break;
                            case "q":
                                doClick(buttons.quote);
                                break;
                            case "k":
                                doClick(buttons.code);
                                break;
                            case "g":
                                doClick(buttons.image);
                                break;
                            case "o":
                                doClick(buttons.olist);
                                break;
                            case "u":
                                doClick(buttons.ulist);
                                break;
                            case "h":
                                doClick(buttons.heading);
                                break;
                            case "r":
                                doClick(buttons.hr);
                                break;
                            case "y":
                                doClick(buttons.redo);
                                break;
                            case "z":
                                if(key.shiftKey) {
                                    doClick(buttons.redo);
                                } else {
                                    doClick(buttons.undo);
                                }
                                break;
                            default:
                                return;
                        }


                        if(key.preventDefault) {
                            key.preventDefault();
                        }

                        if(window.event) {
                            window.event.returnValue = false;
                        }
                    }
                });

                // Auto-indent on shift-enter
                util.addEvent(inputBox, "keyup", function(key) {
                    if(key.shiftKey && !key.ctrlKey && !key.metaKey) {
                        var keyCode = key.charCode || key.keyCode;
                        // Character 13 is Enter
                        if(keyCode === 13) {
                            var fakeButton = {};
                            fakeButton.textOp = bindCommand("doAutoindent");
                            doClick(fakeButton);
                        }
                    }
                });

                // special handler because IE clears the context of the textbox on ESC
                if(uaSniffed.isIE) {
                    util.addEvent(inputBox, "keydown", function(key) {
                        var code = key.keyCode;
                        if(code === 27) {
                            return false;
                        }
                    });
                }


                // Perform the button's action.
                function doClick(button) {

                    inputBox.focus();

                    if(button.textOp) {

                        if(undoManager) {
                            undoManager.setCommandMode();
                        }

                        var state = new ContenteditableState(panels);

                        if(!state) {
                            return;
                        }

                        var chunks = state.getChunks();

                        // Some commands launch a "modal" prompt dialog.  Javascript
                        // can't really make a modal dialog box and the WMD code
                        // will continue to execute while the dialog is displayed.
                        // This prevents the dialog pattern I'm used to and means
                        // I can't do something like this:
                        //
                        // var link = CreateLinkDialog();
                        // makeMarkdownLink(link);
                        //
                        // Instead of this straightforward method of handling a
                        // dialog I have to pass any code which would execute
                        // after the dialog is dismissed (e.g. link creation)
                        // in a function parameter.
                        //
                        // Yes this is awkward and I think it sucks, but there's
                        // no real workaround.  Only the image and link code
                        // create dialogs and require the function pointers.
                        var fixupInputArea = function() {

                            inputBox.focus();

                            if(chunks) {
                                state.setChunks(chunks);
                            }

                            state.restore();
                            previewManager.refresh();
                        };

                        var noCleanup = button.textOp(chunks, fixupInputArea);

                        if(!noCleanup) {
                            fixupInputArea();
                        }

                    }

                    if(button.execute) {
                        button.execute(undoManager);
                    }
                }
                ;

                function setupButton(button, isEnabled) {

                    var normalYShift = "0px";
                    var disabledYShift = "-20px";
                    var highlightYShift = "-40px";
                    var image = button.getElementsByTagName("span")[0];
                    if(isEnabled) {
                        image.style.backgroundPosition = button.XShift + " " + normalYShift;
                        button.onmouseover = function() {
                            image.style.backgroundPosition = this.XShift + " " + highlightYShift;
                        };

                        button.onmouseout = function() {
                            image.style.backgroundPosition = this.XShift + " " + normalYShift;
                        };

                        // IE tries to select the background image "button" text (it's
                        // implemented in a list item) so we have to cache the selection
                        // on mousedown.
                        if(uaSniffed.isIE) {
                            button.onmousedown = function() {
                                if(doc.activeElement && doc.activeElement !== panels.input) { // we're not even in the input box, so there's no selection
                                    return;
                                }
                                panels.ieCachedRange = document.selection.createRange();
                                panels.ieCachedScrollTop = panels.input.scrollTop;
                            };
                        }

                        if(!button.isHelp) {
                            button.onclick = function() {
                                if(this.onmouseout) {
                                    this.onmouseout();
                                }
                                doClick(this);
                                return false;
                            }
                        }
                    } else {
                        image.style.backgroundPosition = button.XShift + " " + disabledYShift;
                        button.onmouseover = button.onmouseout = button.onclick = function() { };
                    }
                }

                function bindCommand(method) {
                    if(typeof method === "string")
                        method = commandManager[method];
                    return function() {
                        method.apply(commandManager, arguments);
                    }
                }

                function makeSpritedButtonRow() {

                    var buttonBar = panels.buttonBar;

                    var normalYShift = "0px";
                    var disabledYShift = "-20px";
                    var highlightYShift = "-40px";

                    var buttonRow = document.createElement("ul");
                    buttonRow.id = "wmd-button-row" + postfix;
                    buttonRow.className = 'wmd-button-row';
                    buttonRow = buttonBar.appendChild(buttonRow);
                    var xPosition = 0;
                    var makeButton = function(id, title, XShift, textOp) {
                        var button = document.createElement("li");
                        button.className = "wmd-button";
                        button.style.left = xPosition + "px";
                        xPosition += 25;
                        var buttonImage = document.createElement("span");
                        button.id = id + postfix;
                        button.appendChild(buttonImage);
                        button.title = title;
                        button.XShift = XShift;
                        if(textOp)
                            button.textOp = textOp;
                        setupButton(button, true);
                        buttonRow.appendChild(button);
                        return button;
                    };
                    var makeSpacer = function(num) {
                        var spacer = document.createElement("li");
                        spacer.className = "wmd-spacer wmd-spacer" + num;
                        spacer.id = "wmd-spacer" + num + postfix;
                        buttonRow.appendChild(spacer);
                        xPosition += 25;
                    }

                    buttons.bold = makeButton("wmd-bold-button", getString("bold"), "0px", bindCommand("doBold"));
                    buttons.italic = makeButton("wmd-italic-button", getString("italic"), "-20px", bindCommand("doItalic"));
                    makeSpacer(1);
                    buttons.link = makeButton("wmd-link-button", getString("link"), "-40px", bindCommand(function(chunk, postProcessing) {
                        return this.doLinkOrImage(chunk, postProcessing, false);
                    }));
                    buttons.quote = makeButton("wmd-quote-button", getString("quote"), "-60px", bindCommand("doBlockquote"));
                    buttons.code = makeButton("wmd-code-button", getString("code"), "-80px", bindCommand("doCode"));
                    buttons.image = makeButton("wmd-image-button", getString("image"), "-100px", bindCommand(function(chunk, postProcessing) {
                        return this.doLinkOrImage(chunk, postProcessing, true);
                    }));
                    makeSpacer(2);
                    buttons.olist = makeButton("wmd-olist-button", getString("olist"), "-120px", bindCommand(function(chunk, postProcessing) {
                        this.doList(chunk, postProcessing, true);
                    }));
                    buttons.ulist = makeButton("wmd-ulist-button", getString("ulist"), "-140px", bindCommand(function(chunk, postProcessing) {
                        this.doList(chunk, postProcessing, false);
                    }));
                    buttons.heading = makeButton("wmd-heading-button", getString("heading"), "-160px", bindCommand("doHeading"));
                    buttons.hr = makeButton("wmd-hr-button", getString("hr"), "-180px", bindCommand("doHorizontalRule"));
                    makeSpacer(3);
                    buttons.undo = makeButton("wmd-undo-button", getString("undo"), "-200px", null);
                    buttons.undo.execute = function(manager) {
                        if(manager)
                            manager.undo();
                    };

                    var redoTitle = /win/.test(nav.platform.toLowerCase()) ?
                            getString("redo") :
                            getString("redomac"); // mac and other non-Windows platforms

                    buttons.redo = makeButton("wmd-redo-button", redoTitle, "-220px", null);
                    buttons.redo.execute = function(manager) {
                        if(manager)
                            manager.redo();
                    };

                    if(helpOptions) {
                        var helpButton = document.createElement("li");
                        var helpButtonImage = document.createElement("span");
                        helpButton.appendChild(helpButtonImage);
                        helpButton.className = "wmd-button wmd-help-button";
                        helpButton.id = "wmd-help-button" + postfix;
                        helpButton.XShift = "-240px";
                        helpButton.isHelp = true;
                        helpButton.style.right = "0px";
                        helpButton.title = getString("help");
                        helpButton.onclick = helpOptions.handler;

                        setupButton(helpButton, true);
                        buttonRow.appendChild(helpButton);
                        buttons.help = helpButton;
                    }

                    setUndoRedoButtonStates();
                }

                function setUndoRedoButtonStates() {
                    if(undoManager) {
                        setupButton(buttons.undo, undoManager.canUndo());
                        setupButton(buttons.redo, undoManager.canRedo());
                    }
                }
                ;

                this.setUndoRedoButtonStates = setUndoRedoButtonStates;

            }

            function CommandManager(pluginHooks, getString, converter) {
                this.hooks = pluginHooks;
                this.getString = getString;
                this.converter = converter;
            }

            var commandProto = CommandManager.prototype;

            // The markdown symbols - 4 spaces = code, > = blockquote, etc.
            commandProto.prefixes = "(?:\\s{4,}|\\s*>|\\s*-\\s+|\\s*\\d+\\.|=|\\+|-|_|\\*|#|\\s*\\[[^\n]]+\\]:)";

            // Remove markdown symbols from the chunk selection.
            commandProto.unwrap = function(chunk) {
                var txt = new re("([^\\n])\\n(?!(\\n|" + this.prefixes + "))", "g");
                chunk.selection = chunk.selection.replace(txt, "$1 $2");
            };

            commandProto.wrap = function(chunk, len) {
                this.unwrap(chunk);
                var regex = new re("(.{1," + len + "})( +|$\\n?)", "gm"),
                        that = this;

                chunk.selection = chunk.selection.replace(regex, function(line, marked) {
                    if(new re("^" + that.prefixes, "").test(line)) {
                        return line;
                    }
                    return marked + "\n";
                });

                chunk.selection = chunk.selection.replace(/\s+$/, "");
            };

            commandProto.doBold = function(chunk, postProcessing) {
                return this.doBorI(chunk, postProcessing, 2, this.getString("boldexample"));
            };

            commandProto.doItalic = function(chunk, postProcessing) {
                return this.doBorI(chunk, postProcessing, 1, this.getString("italicexample"));
            };

            // chunk: The selected region that will be enclosed with */**
            // nStars: 1 for italics, 2 for bold
            // insertText: If you just click the button without highlighting text, this gets inserted
            commandProto.doBorI = function(chunk, postProcessing, nStars, insertText) {

                // Get rid of whitespace and fixup newlines.
                chunk.trimWhitespace();
                chunk.selection = chunk.selection.replace(/\n{2,}/g, "\n");

                // Look for stars before and after.  Is the chunk already marked up?
                // note that these regex matches cannot fail
                var starsBefore = /(\**$)/.exec(chunk.before)[0];
                var starsAfter = /(^\**)/.exec(chunk.after)[0];

                var prevStars = Math.min(starsBefore.length, starsAfter.length);

                // Remove stars if we have to since the button acts as a toggle.
                if((prevStars >= nStars) && (prevStars != 2 || nStars != 1)) {
                    chunk.before = chunk.before.replace(re("[*]{" + nStars + "}$", ""), "");
                    chunk.after = chunk.after.replace(re("^[*]{" + nStars + "}", ""), "");
                } else if(!chunk.selection && starsAfter) {
                    // It's not really clear why this code is necessary.  It just moves
                    // some arbitrary stuff around.
                    chunk.after = chunk.after.replace(/^([*_]*)/, "");
                    chunk.before = chunk.before.replace(/(\s?)$/, "");
                    var whitespace = re.$1;
                    chunk.before = chunk.before + starsAfter + whitespace;
                } else {

                    // In most cases, if you don't have any selected text and click the button
                    // you'll get a selected, marked up region with the default text inserted.
                    if(!chunk.selection && !starsAfter) {
                        chunk.selection = insertText;
                    }

                    // Add the true markup.
                    var markup = nStars <= 1 ? "*" : "**"; // shouldn't the test be = ?
                    chunk.before = chunk.before + markup;
                    chunk.after = markup + chunk.after;
                }

                return;
            };

            commandProto.stripLinkDefs = function(text, defsToAdd) {

                text = text.replace(/^[ ]{0,3}\[(\d+)\]:[ \t]*\n?[ \t]*<?(\S+?)>?[ \t]*\n?[ \t]*(?:(\n*)["(](.+?)[")][ \t]*)?(?:\n+|$)/gm,
                        function(totalMatch, id, link, newlines, title) {
                            defsToAdd[id] = totalMatch.replace(/\s*$/, "");
                            if(newlines) {
                                // Strip the title and return that separately.
                                defsToAdd[id] = totalMatch.replace(/["(](.+?)[")]$/, "");
                                return newlines + title;
                            }
                            return "";
                        });

                return text;
            };

            commandProto.addLinkDef = function(chunk, linkDef) {

                var refNumber = 0; // The current reference number
                var defsToAdd = {}; //
                // Start with a clean slate by removing all previous link definitions.
                chunk.before = this.stripLinkDefs(chunk.before, defsToAdd);
                chunk.selection = this.stripLinkDefs(chunk.selection, defsToAdd);
                chunk.after = this.stripLinkDefs(chunk.after, defsToAdd);

                var defs = "";
                var regex = /(\[)((?:\[[^\]]*\]|[^\[\]])*)(\][ ]?(?:\n[ ]*)?\[)(\d+)(\])/g;

                // The above regex, used to update [foo][13] references after renumbering,
                // is much too liberal; it can catch things that are not actually parsed
                // as references (notably: code). It's impossible to know which matches are
                // real references without performing a markdown conversion, so that's what
                // we do. All matches are replaced with a unique reference number, which is
                // given a unique link. The uniquifier in both cases is the character offset
                // of the match inside the source string. The modified version is then sent
                // through the Markdown renderer. Because link reference are stripped during
                // rendering, the unique link is present in the rendered version if and only
                // if the match at its offset was in fact rendered as a link or image.
                var complete = chunk.before + chunk.selection + chunk.after;
                var rendered = this.converter.makeHtml(complete);
                var testlink = "http://this-is-a-real-link.biz/";

                // If our fake link appears in the rendered version *before* we have added it,
                // this probably means you're a Meta Stack Exchange user who is deliberately
                // trying to break this feature. You can still break this workaround if you
                // attach a plugin to the converter that sometimes (!) inserts this link. In
                // that case, consider yourself unsupported.
                while(rendered.indexOf(testlink) != - 1)
                    testlink += "nicetry/";

                var fakedefs = "\n\n";

                // the regex is tested on the (up to) three chunks separately, and on substrings,
                // so in order to have the correct offsets to check against okayToModify(), we
                // have to keep track of how many characters are in the original source before
                // the substring that we're looking at. Note that doLinkOrImage aligns the selection
                // on potential brackets, so there should be no major breakage from the chunk
                // separation.
                var skippedChars = 0;

                var uniquified = complete.replace(regex, function uniquify(wholeMatch, before, inner, afterInner, id, end, offset) {
                    skippedChars += offset;
                    fakedefs += " [" + skippedChars + "]: " + testlink + skippedChars + "/unicorn\n";
                    skippedChars += before.length;
                    inner = inner.replace(regex, uniquify);
                    skippedChars -= before.length;
                    var result = before + inner + afterInner + skippedChars + end;
                    skippedChars -= offset;
                    return result;
                });

                rendered = this.converter.makeHtml(uniquified + fakedefs);

                var okayToModify = function(offset) {
                    return rendered.indexOf(testlink + offset + "/unicorn") !== -1;
                }

                var addDefNumber = function(def) {
                    refNumber++;
                    def = def.replace(/^[ ]{0,3}\[(\d+)\]:/, "  [" + refNumber + "]:");
                    defs += "\n" + def;
                };

                // note that
                // a) the recursive call to getLink cannot go infinite, because by definition
                //    of regex, inner is always a proper substring of wholeMatch, and
                // b) more than one level of nesting is neither supported by the regex
                //    nor making a lot of sense (the only use case for nesting is a linked image)
                var getLink = function(wholeMatch, before, inner, afterInner, id, end, offset) {
                    if(!okayToModify(skippedChars + offset))
                        return wholeMatch;
                    skippedChars += offset + before.length;
                    inner = inner.replace(regex, getLink);
                    skippedChars -= offset + before.length;
                    if(defsToAdd[id]) {
                        addDefNumber(defsToAdd[id]);
                        return before + inner + afterInner + refNumber + end;
                    }
                    return wholeMatch;
                };

                var len = chunk.before.length;
                chunk.before = chunk.before.replace(regex, getLink);
                skippedChars += len;

                len = chunk.selection.length;
                if(linkDef) {
                    addDefNumber(linkDef);
                } else {
                    chunk.selection = chunk.selection.replace(regex, getLink);
                }
                skippedChars += len;

                var refOut = refNumber;

                chunk.after = chunk.after.replace(regex, getLink);

                if(chunk.after) {
                    chunk.after = chunk.after.replace(/\n*$/, "");
                }
                if(!chunk.after) {
                    chunk.selection = chunk.selection.replace(/\n*$/, "");
                }

                chunk.after += "\n\n" + defs;

                return refOut;
            };

            // takes the line as entered into the add link/as image dialog and makes
            // sure the URL and the optinal title are "nice".
            function properlyEncoded(linkdef) {
                return linkdef.replace(/^\s*(.*?)(?:\s+"(.+)")?\s*$/, function(wholematch, link, title) {

                    var inQueryString = false;

                    // Having `[^\w\d-./]` in there is just a shortcut that lets us skip
                    // the most common characters in URLs. Replacing that it with `.` would not change
                    // the result, because encodeURI returns those characters unchanged, but it
                    // would mean lots of unnecessary replacement calls. Having `[` and `]` in that
                    // section as well means we do *not* enocde square brackets. These characters are
                    // a strange beast in URLs, but if anything, this causes URLs to be more readable,
                    // and we leave it to the browser to make sure that these links are handled without
                    // problems.
                    link = link.replace(/%(?:[\da-fA-F]{2})|\?|\+|[^\w\d-./[\]]/g, function(match) {
                        // Valid percent encoding. Could just return it as is, but we follow RFC3986
                        // Section 2.1 which says "For consistency, URI producers and normalizers
                        // should use uppercase hexadecimal digits for all percent-encodings."
                        // Note that we also handle (illegal) stand-alone percent characters by
                        // replacing them with "%25"
                        if(match.length === 3 && match.charAt(0) == "%") {
                            return match.toUpperCase();
                        }
                        switch(match) {
                            case "?":
                                inQueryString = true;
                                return "?";
                                break;

                                // In the query string, a plus and a space are identical -- normalize.
                                // Not strictly necessary, but identical behavior to the previous version
                                // of this function.
                            case "+":
                                if(inQueryString)
                                    return "%20";
                                break;
                        }
                        return encodeURI(match);
                    })

                    if(title) {
                        title = title.trim ? title.trim() : title.replace(/^\s*/, "").replace(/\s*$/, "");
                        title = title.replace(/"/g, "quot;").replace(/\(/g, "&#40;").replace(/\)/g, "&#41;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
                    }
                    return title ? link + ' "' + title + '"' : link;
                });
            }

            commandProto.doLinkOrImage = function(chunk, postProcessing, isImage) {

                chunk.trimWhitespace();
                chunk.findTags(/\s*!?\[/, /\][ ]?(?:\n[ ]*)?(\[.*?\])?/);
                var background;

                if(chunk.endTag.length > 1 && chunk.startTag.length > 0) {

                    chunk.startTag = chunk.startTag.replace(/!?\[/, "");
                    chunk.endTag = "";
                    this.addLinkDef(chunk, null);

                } else {

                    // We're moving start and end tag back into the selection, since (as we're in the else block) we're not
                    // *removing* a link, but *adding* one, so whatever findTags() found is now back to being part of the
                    // link text. linkEnteredCallback takes care of escaping any brackets.
                    chunk.selection = chunk.startTag + chunk.selection + chunk.endTag;
                    chunk.startTag = chunk.endTag = "";

                    if(/\n\n/.test(chunk.selection)) {
                        this.addLinkDef(chunk, null);
                        return;
                    }
                    var that = this;
                    // The function to be executed when you enter a link and press OK or Cancel.
                    // Marks up the link and adds the ref.
                    var linkEnteredCallback = function(link) {

                        background.parentNode.removeChild(background);

                        if(link !== null) {
                            // (                          $1
                            //     [^\\]                  anything that's not a backslash
                            //     (?:\\\\)*              an even number (this includes zero) of backslashes
                            // )
                            // (?=                        followed by
                            //     [[\]]                  an opening or closing bracket
                            // )
                            //
                            // In other words, a non-escaped bracket. These have to be escaped now to make sure they
                            // don't count as the end of the link or similar.
                            // Note that the actual bracket has to be a lookahead, because (in case of to subsequent brackets),
                            // the bracket in one match may be the "not a backslash" character in the next match, so it
                            // should not be consumed by the first match.
                            // The "prepend a space and finally remove it" steps makes sure there is a "not a backslash" at the
                            // start of the string, so this also works if the selection begins with a bracket. We cannot solve
                            // this by anchoring with ^, because in the case that the selection starts with two brackets, this
                            // would mean a zero-width match at the start. Since zero-width matches advance the string position,
                            // the first bracket could then not act as the "not a backslash" for the second.
                            chunk.selection = (" " + chunk.selection).replace(/([^\\](?:\\\\)*)(?=[[\]])/g, "$1\\").substr(1);

                            var linkDef = " [999]: " + properlyEncoded(link);

                            var num = that.addLinkDef(chunk, linkDef);
                            chunk.startTag = isImage ? "![" : "[";
                            chunk.endTag = "][" + num + "]";

                            if(!chunk.selection) {
                                if(isImage) {
                                    chunk.selection = that.getString("imagedescription");
                                } else {
                                    chunk.selection = that.getString("linkdescription");
                                }
                            }
                        }
                        postProcessing();
                    };

                    background = ui.createBackground();

                    if(isImage) {
                        if(!this.hooks.insertImageDialog(linkEnteredCallback))
                            ui.prompt(this.getString("imagedialog"), imageDefaultText, linkEnteredCallback);
                    } else {
                        ui.prompt(this.getString("linkdialog"), linkDefaultText, linkEnteredCallback);
                    }
                    return true;
                }
            };

            // When making a list, hitting shift-enter will put your cursor on the next line
            // at the current indent level.
            commandProto.doAutoindent = function(chunk, postProcessing) {

                var commandMgr = this,
                        fakeSelection = false;

                chunk.before = chunk.before.replace(/(\n|^)[ ]{0,3}([*+-]|\d+[.])[ \t]*\n$/, "\n\n");
                chunk.before = chunk.before.replace(/(\n|^)[ ]{0,3}>[ \t]*\n$/, "\n\n");
                chunk.before = chunk.before.replace(/(\n|^)[ \t]+\n$/, "\n\n");

                // There's no selection, end the cursor wasn't at the end of the line:
                // The user wants to split the current list item / code line / blockquote line
                // (for the latter it doesn't really matter) in two. Temporarily select the
                // (rest of the) line to achieve this.
                if(!chunk.selection && !/^[ \t]*(?:\n|$)/.test(chunk.after)) {
                    chunk.after = chunk.after.replace(/^[^\n]*/, function(wholeMatch) {
                        chunk.selection = wholeMatch;
                        return "";
                    });
                    fakeSelection = true;
                }

                if(/(\n|^)[ ]{0,3}([*+-]|\d+[.])[ \t]+.*\n$/.test(chunk.before)) {
                    if(commandMgr.doList) {
                        commandMgr.doList(chunk);
                    }
                }
                if(/(\n|^)[ ]{0,3}>[ \t]+.*\n$/.test(chunk.before)) {
                    if(commandMgr.doBlockquote) {
                        commandMgr.doBlockquote(chunk);
                    }
                }
                if(/(\n|^)(\t|[ ]{4,}).*\n$/.test(chunk.before)) {
                    if(commandMgr.doCode) {
                        commandMgr.doCode(chunk);
                    }
                }

                if(fakeSelection) {
                    chunk.after = chunk.selection + chunk.after;
                    chunk.selection = "";
                }
            };

            commandProto.doBlockquote = function(chunk, postProcessing) {

                chunk.selection = chunk.selection.replace(/^(\n*)([^\r]+?)(\n*)$/,
                        function(totalMatch, newlinesBefore, text, newlinesAfter) {
                            chunk.before += newlinesBefore;
                            chunk.after = newlinesAfter + chunk.after;
                            return text;
                        });

                chunk.before = chunk.before.replace(/(>[ \t]*)$/,
                        function(totalMatch, blankLine) {
                            chunk.selection = blankLine + chunk.selection;
                            return "";
                        });

                chunk.selection = chunk.selection.replace(/^(\s|>)+$/, "");
                chunk.selection = chunk.selection || this.getString("quoteexample");

                // The original code uses a regular expression to find out how much of the
                // text *directly before* the selection already was a blockquote:

                /*
                 if (chunk.before) {
                 chunk.before = chunk.before.replace(/\n?$/, "\n");
                 }
                 chunk.before = chunk.before.replace(/(((\n|^)(\n[ \t]*)*>(.+\n)*.*)+(\n[ \t]*)*$)/,
                 function (totalMatch) {
                 chunk.startTag = totalMatch;
                 return "";
                 });
                 */

                // This comes down to:
                // Go backwards as many lines a possible, such that each line
                //  a) starts with ">", or
                //  b) is almost empty, except for whitespace, or
                //  c) is preceeded by an unbroken chain of non-empty lines
                //     leading up to a line that starts with ">" and at least one more character
                // and in addition
                //  d) at least one line fulfills a)
                //
                // Since this is essentially a backwards-moving regex, it's susceptible to
                // catstrophic backtracking and can cause the browser to hang;
                // see e.g. http://meta.stackexchange.com/questions/9807.
                //
                // Hence we replaced this by a simple state machine that just goes through the
                // lines and checks for a), b), and c).

                var match = "",
                        leftOver = "",
                        line;
                if(chunk.before) {
                    var lines = chunk.before.replace(/\n$/, "").split("\n");
                    var inChain = false;
                    for(var i = 0; i < lines.length; i++) {
                        var good = false;
                        line = lines[i];
                        inChain = inChain && line.length > 0; // c) any non-empty line continues the chain
                        if(/^>/.test(line)) {                // a)
                            good = true;
                            if(!inChain && line.length > 1)  // c) any line that starts with ">" and has at least one more character starts the chain
                                inChain = true;
                        } else if(/^[ \t]*$/.test(line)) {   // b)
                            good = true;
                        } else {
                            good = inChain;                   // c) the line is not empty and does not start with ">", so it matches if and only if we're in the chain
                        }
                        if(good) {
                            match += line + "\n";
                        } else {
                            leftOver += match + line;
                            match = "\n";
                        }
                    }
                    if(!/(^|\n)>/.test(match)) {             // d)
                        leftOver += match;
                        match = "";
                    }
                }

                chunk.startTag = match;
                chunk.before = leftOver;

                // end of change

                if(chunk.after) {
                    chunk.after = chunk.after.replace(/^\n?/, "\n");
                }

                chunk.after = chunk.after.replace(/^(((\n|^)(\n[ \t]*)*>(.+\n)*.*)+(\n[ \t]*)*)/,
                        function(totalMatch) {
                            chunk.endTag = totalMatch;
                            return "";
                        }
                );

                var replaceBlanksInTags = function(useBracket) {

                    var replacement = useBracket ? "> " : "";

                    if(chunk.startTag) {
                        chunk.startTag = chunk.startTag.replace(/\n((>|\s)*)\n$/,
                                function(totalMatch, markdown) {
                                    return "\n" + markdown.replace(/^[ ]{0,3}>?[ \t]*$/gm, replacement) + "\n";
                                });
                    }
                    if(chunk.endTag) {
                        chunk.endTag = chunk.endTag.replace(/^\n((>|\s)*)\n/,
                                function(totalMatch, markdown) {
                                    return "\n" + markdown.replace(/^[ ]{0,3}>?[ \t]*$/gm, replacement) + "\n";
                                });
                    }
                };

                if(/^(?![ ]{0,3}>)/m.test(chunk.selection)) {
                    this.wrap(chunk, SETTINGS.lineLength - 2);
                    chunk.selection = chunk.selection.replace(/^/gm, "> ");
                    replaceBlanksInTags(true);
                    chunk.skipLines();
                } else {
                    chunk.selection = chunk.selection.replace(/^[ ]{0,3}> ?/gm, "");
                    this.unwrap(chunk);
                    replaceBlanksInTags(false);

                    if(!/^(\n|^)[ ]{0,3}>/.test(chunk.selection) && chunk.startTag) {
                        chunk.startTag = chunk.startTag.replace(/\n{0,2}$/, "\n\n");
                    }

                    if(!/(\n|^)[ ]{0,3}>.*$/.test(chunk.selection) && chunk.endTag) {
                        chunk.endTag = chunk.endTag.replace(/^\n{0,2}/, "\n\n");
                    }
                }

                chunk.selection = this.hooks.postBlockquoteCreation(chunk.selection);

                if(!/\n/.test(chunk.selection)) {
                    chunk.selection = chunk.selection.replace(/^(> *)/,
                            function(wholeMatch, blanks) {
                                chunk.startTag += blanks;
                                return "";
                            });
                }
            };

            commandProto.doCode = function(chunk, postProcessing) {

                var hasTextBefore = /\S[ ]*$/.test(chunk.before);
                var hasTextAfter = /^[ ]*\S/.test(chunk.after);

                // Use 'four space' markdown if the selection is on its own
                // line or is multiline.
                if((!hasTextAfter && !hasTextBefore) || /\n/.test(chunk.selection)) {

                    chunk.before = chunk.before.replace(/[ ]{4}$/,
                            function(totalMatch) {
                                chunk.selection = totalMatch + chunk.selection;
                                return "";
                            });

                    var nLinesBack = 1;
                    var nLinesForward = 1;

                    if(/(\n|^)(\t|[ ]{4,}).*\n$/.test(chunk.before)) {
                        nLinesBack = 0;
                    }
                    if(/^\n(\t|[ ]{4,})/.test(chunk.after)) {
                        nLinesForward = 0;
                    }

                    chunk.skipLines(nLinesBack, nLinesForward);

                    if(!chunk.selection) {
                        chunk.startTag = "    ";
                        chunk.selection = this.getString("codeexample");
                    } else {
                        if(/^[ ]{0,3}\S/m.test(chunk.selection)) {
                            if(/\n/.test(chunk.selection))
                                chunk.selection = chunk.selection.replace(/^/gm, "    ");
                            else // if it's not multiline, do not select the four added spaces; this is more consistent with the doList behavior
                                chunk.before += "    ";
                        } else {
                            chunk.selection = chunk.selection.replace(/^(?:[ ]{4}|[ ]{0,3}\t)/gm, "");
                        }
                    }
                } else {
                    // Use backticks (`) to delimit the code block.

                    chunk.trimWhitespace();
                    chunk.findTags(/`/, /`/);

                    if(!chunk.startTag && !chunk.endTag) {
                        chunk.startTag = chunk.endTag = "`";
                        if(!chunk.selection) {
                            chunk.selection = this.getString("codeexample");
                        }
                    } else if(chunk.endTag && !chunk.startTag) {
                        chunk.before += chunk.endTag;
                        chunk.endTag = "";
                    } else {
                        chunk.startTag = chunk.endTag = "";
                    }
                }
            };

            commandProto.doList = function(chunk, postProcessing, isNumberedList) {

                // These are identical except at the very beginning and end.
                // Should probably use the regex extension function to make this clearer.
                var previousItemsRegex = /(\n|^)(([ ]{0,3}([*+-]|\d+[.])[ \t]+.*)(\n.+|\n{2,}([*+-].*|\d+[.])[ \t]+.*|\n{2,}[ \t]+\S.*)*)\n*$/;
                var nextItemsRegex = /^\n*(([ ]{0,3}([*+-]|\d+[.])[ \t]+.*)(\n.+|\n{2,}([*+-].*|\d+[.])[ \t]+.*|\n{2,}[ \t]+\S.*)*)\n*/;

                // The default bullet is a dash but others are possible.
                // This has nothing to do with the particular HTML bullet,
                // it's just a markdown bullet.
                var bullet = "-";

                // The number in a numbered list.
                var num = 1;

                // Get the item prefix - e.g. " 1. " for a numbered list, " - " for a bulleted list.
                var getItemPrefix = function() {
                    var prefix;
                    if(isNumberedList) {
                        prefix = " " + num + ". ";
                        num++;
                    } else {
                        prefix = " " + bullet + " ";
                    }
                    return prefix;
                };

                // Fixes the prefixes of the other list items.
                var getPrefixedItem = function(itemText) {

                    // The numbering flag is unset when called by autoindent.
                    if(isNumberedList === undefined) {
                        isNumberedList = /^\s*\d/.test(itemText);
                    }

                    // Renumber/bullet the list element.
                    itemText = itemText.replace(/^[ ]{0,3}([*+-]|\d+[.])\s/gm,
                            function(_) {
                                return getItemPrefix();
                            });

                    return itemText;
                };

                chunk.findTags(/(\n|^)*[ ]{0,3}([*+-]|\d+[.])\s+/, null);

                if(chunk.before && !/\n$/.test(chunk.before) && !/^\n/.test(chunk.startTag)) {
                    chunk.before += chunk.startTag;
                    chunk.startTag = "";
                }

                if(chunk.startTag) {

                    var hasDigits = /\d+[.]/.test(chunk.startTag);
                    chunk.startTag = "";
                    chunk.selection = chunk.selection.replace(/\n[ ]{4}/g, "\n");
                    this.unwrap(chunk);
                    chunk.skipLines();

                    if(hasDigits) {
                        // Have to renumber the bullet points if this is a numbered list.
                        chunk.after = chunk.after.replace(nextItemsRegex, getPrefixedItem);
                    }
                    if(isNumberedList == hasDigits) {
                        return;
                    }
                }

                var nLinesUp = 1;

                chunk.before = chunk.before.replace(previousItemsRegex,
                        function(itemText) {
                            if(/^\s*([*+-])/.test(itemText)) {
                                bullet = re.$1;
                            }
                            nLinesUp = /[^\n]\n\n[^\n]/.test(itemText) ? 1 : 0;
                            return getPrefixedItem(itemText);
                        });

                if(!chunk.selection) {
                    chunk.selection = this.getString("litem");
                }

                var prefix = getItemPrefix();

                var nLinesDown = 1;

                chunk.after = chunk.after.replace(nextItemsRegex,
                        function(itemText) {
                            nLinesDown = /[^\n]\n\n[^\n]/.test(itemText) ? 1 : 0;
                            return getPrefixedItem(itemText);
                        });

                chunk.trimWhitespace(true);
                chunk.skipLines(nLinesUp, nLinesDown, true);
                chunk.startTag = prefix;
                var spaces = prefix.replace(/./g, " ");
                this.wrap(chunk, SETTINGS.lineLength - spaces.length);
                chunk.selection = chunk.selection.replace(/\n/g, "\n" + spaces);

            };

            commandProto.doHeading = function(chunk, postProcessing) {

                // Remove leading/trailing whitespace and reduce internal spaces to single spaces.
                chunk.selection = chunk.selection.replace(/\s+/g, " ");
                chunk.selection = chunk.selection.replace(/(^\s+|\s+$)/g, "");

                // If we clicked the button with no selected text, we just
                // make a level 2 hash header around some default text.
                if(!chunk.selection) {
                    chunk.startTag = "## ";
                    chunk.selection = this.getString("headingexample");
                    chunk.endTag = " ##";
                    return;
                }

                var headerLevel = 0;     // The existing header level of the selected text.

                // Remove any existing hash heading markdown and save the header level.
                chunk.findTags(/#+[ ]*/, /[ ]*#+/);
                if(/#+/.test(chunk.startTag)) {
                    headerLevel = re.lastMatch.length;
                }
                chunk.startTag = chunk.endTag = "";

                // Try to get the current header level by looking for - and = in the line
                // below the selection.
                chunk.findTags(null, /\s?(-+|=+)/);
                if(/=+/.test(chunk.endTag)) {
                    headerLevel = 1;
                }
                if(/-+/.test(chunk.endTag)) {
                    headerLevel = 2;
                }

                // Skip to the next line so we can create the header markdown.
                chunk.startTag = chunk.endTag = "";
                chunk.skipLines(1, 1);

                // We make a level 2 header if there is no current header.
                // If there is a header level, we substract one from the header level.
                // If it's already a level 1 header, it's removed.
                var headerLevelToCreate = headerLevel == 0 ? 2 : headerLevel - 1;

                if(headerLevelToCreate > 0) {

                    // The button only creates level 1 and 2 underline headers.
                    // Why not have it iterate over hash header levels?  Wouldn't that be easier and cleaner?
                    var headerChar = headerLevelToCreate >= 2 ? "-" : "=";
                    var len = chunk.selection.length;
                    if(len > SETTINGS.lineLength) {
                        len = SETTINGS.lineLength;
                    }
                    chunk.endTag = "\n";
                    while(len--) {
                        chunk.endTag += headerChar;
                    }
                }
            };

            commandProto.doHorizontalRule = function(chunk, postProcessing) {
                chunk.startTag = "----------\n";
                chunk.selection = "";
                chunk.skipLines(2, 1, true);
            }


        })();