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;