var jshover = function() {
  var sfEls = document.getElementById("horizontal-multilevel-menu").getElementsByTagName("li");
  for (var i=0; i<sfEls.length; i++) 
  {
    sfEls[i].onmouseover=function()
    {
      this.className+=" jshover";
    }
    sfEls[i].onmouseout=function() 
    {
      this.className=this.className.replace(new RegExp(" jshover\\b"), "");
    }
  }
}

if (window.attachEvent) 
  window.attachEvent("onload", jshover);