<script type="text/javascript">

    Event.observe(window, 'load', function() {
        $$('#nav li.level0 > ul.level0').invoke('hide');
        $$("#nav li.parent").each(function(elem){if (elem.hasAttribute("onmouseover")) {
            elem.removeAttribute("onmouseover")}
        });

        $$("#nav li.parent").each(function(elem){if (elem.hasAttribute("onmouseout")) {
            elem.removeAttribute("onmouseout")}
        });
    });

    Event.observe($$('#nav li.parent'), 'mouseover', function(){
        this.down('ul').goDown(this);
    });

    function goDown(element){
       new Effect.SlideDown(element, {duration:0.5});
    }

    function goUp(element){
       new Effect.SlideUp(element, {duration:0.5});
    }

</script>