hover = function() {
	var els = document.getElementById("lvl0").getElementsByTagName("li");
	var elsCells = document.getElementById("lvl0").getElementsByTagName("td");
	for (var i=0; i<elsCells.length; i++) {
		elsCells[i].onmouseover=function() {
			this.className+=" hover";
		}
		elsCells[i].onmouseout=function() {
			this.className=this.className.replace(new RegExp(" hover\\b"), "");
		}							
	}						
	for (var i=0; i<els.length; i++) {
		els[i].onmouseover=function() {
			this.className+=" hover";
		}
		els[i].onmouseout=function() {
			this.className=this.className.replace(new RegExp(" hover\\b"), "");
		}							
	}						
}
if (window.attachEvent){
	window.attachEvent("onload", hover);
}