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