startList = function()
{
  var navRoot = document.getElementById("horizontal_nav_menu");
  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", "");
      }
    }
  }
}
if (window.attachEvent) window.attachEvent("onload", startList);