var images = ['img/icons/home.gif', 'img/icons/homeAct.gif', 'img/icons/map.gif', 'img/icons/mapAct.gif'];
var preloaded = [];
for (var i=0; i<images.length; i++)
{
    preloaded[i] = new Image;
	preloaded[i].src = images[i];
}

startList = function() {
if (document.all&&document.getElementById) {
navRoot = document.getElementById("nav");
for (i=0; i<navRoot.childNodes.length; i++) {
node = navRoot.childNodes[i];
if (node.nodeName=="LI") {
node.onmouseover=function() {
this.className+="over";
  }
  node.onmouseout=function() {
  this.className=this.className.replace("over", "");
   }
   }
  }
 }
}
window.onload=startList;