$(function(){
    $("#menu ul > li > ul, #menu ul > li > ul > li > ul").hide();
		
		$("#menu ul > li.opened > ul, #menu ul > li > ul > li.opened > ul").slideDown(400);
		
    $("#menu ul > li, #menu ul > li > ul > li").click(function(){

        if ($("#nav ul:animated").size() == 0) {

            $heading = $(this);
            // create a reference to visible sibling elements
            // so we don"t have to keep creating a jQuery object
            $expandedSiblings = $heading.siblings().find("ul:visible");
            if ($expandedSiblings.size() > 0) {
                $expandedSiblings.slideUp(400, function(){
                    $heading.children("ul").slideDown(400);
                });
            }
            else {
                $heading.children("ul").slideDown(400);
            }
        }	
    });
});