var ul = document.getElementById("mainlevelnav").getElementsByTagName("ul");
	for(var i=0, l=ul.length; i<l; i++) {
		var li = ul[i].parentNode;
		li.list = ul[i];
		li.ls = ul[i].style;
		li.onmouseover = showup;
		li.onmouseout = disappear;
	}	
	
	function showup() {
		if (this.up) clearTimeout(this.up);
		this.ls.visibility = 'visible';
	}			
	
	function disappear() {
		var me = this;
		this.up = setTimeout(function(){me.ls.visibility = 'hidden';}, 400);	
	}