startList = function() {
	if (document.all && document.getElementById) { //the browser can run script
		navRoot = document.getElementById("nav"); //find nav element
		for (i=0; i<navRoot.childNodes.length; i++) { //loop through nav's childnodes
			node = navRoot.childNodes[i];
			if (node.nodeName=="LI") { //if nodename is li (node is a list item)
				node.onmouseover=function() {	
					this.className+=" over"; //adds over to class name
				}
				node.onmouseout=function() {
					this.className=	this.className.replace(" over", ""); //removes over from class name
				}
			}
		}
	}
}
window.onload=startList; //runs script on page load