View file application/appearance/account/elements/language.tpl

<div class="Language">
	<select class="changeLanguage form-select">
		<option value="kz" {if(isset($_SESSION['lang']) AND $_SESSION['lang'] == 'kz')} selected {/if}>Қазақша</option>
		<option value="ru" {if(isset($_SESSION['lang']) AND $_SESSION['lang'] == 'ru')} selected {/if}>Русский</option>
		<option value="en" {if(isset($_SESSION['lang']) AND $_SESSION['lang'] == 'en')} selected {/if}>English</option>
	</select>
					
	<script>
		$('.changeLanguage').change(function() {
			switch($(this).val()) {
				case 'kz': {
					location.href = "/account/language?lang=kz&redirect={echo($_SERVER['REQUEST_URI'])}";
					break;
				}
				
				case 'en': {
					location.href = "/account/language?lang=en&redirect={echo($_SERVER['REQUEST_URI'])}";
					break;
				}
				
				default: {
					location.href = "/account/language?lang=ru&redirect={echo($_SERVER['REQUEST_URI'])}";
				}
			}
		});
	</script>
</div>