startList = function() {
	if (document.all&&document.getElementById) {
		t_ds = document.getElementById("main_nav").getElementsByTagName('TD');
		for (t in t_ds) {
			node = t_ds[t];
			if (node.nodeName=="TD") {
				node.onmouseover=function() {
					this.className+=" over";
				}
				node.onmouseout=function() {
					this.className=this.className.replace(" over", "");
				}
			}
		}
	}
}