startmenu = function() {
  if (document.all&&document.getElementById) {
    cssmenu = document.getElementById("csstopmenu");
    for (i=0; i<cssmenu.childNodes.length; i++) {
      node = cssmenu.childNodes[i];
      if (node.nodeName=="LI") {
        node.onmouseover=function() {
          this.className+=" over";
        }
        node.onmouseout=function(){                  
          this.className=this.className.replace(" over", "")
        }
      }
    }
  }
}

if (window.attachEvent) {
  window.attachEvent("onload", startmenu);
}
else {
  window.onload(startmenu);
}