$(document).ready(function() { 

	$('#Content div.MessageForm.CommentForm div.Tabs.CommentTabs ul').append('<li><a href="javascript:;" class="Spoiled">Spoiler</a></li>');
	
	jQuery(function() {
	    // Bind the click handler of some button on your page
	    jQuery('.Spoiled').click(function(evt) {
	        // Insert the selected text into a given textarea
	        var textarea = jQuery('textarea#Form_Body.TextBox');
	        textarea.val('[spoiler]'+ textarea.val() + getSelectedText() + '[/spoiler]');
	        evt.preventDefault();
	    });
	});
	
	// Get user selection text on page
	function getSelectedText() {
	    if (window.getSelection) {
	        return window.getSelection();
	    }
	    else if (document.selection) {
	        return document.selection.createRange().text;
	    }
	    return '';
	}

});