startList = function() {
    if (document.all && document.getElementById) {
	navRoot = document.getElementById("nav_main");
	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;