function setup_menu ()
{
 if (document.all && document.getElementById)
 {
 var menu = document.getElementById("main_menu");
 var node;
 for (var i=0; i < menu.childNodes.length; i++)
 {
   node = menu.childNodes[i];
   if (node.nodeName=="LI")
   {
	node.onmouseover=function() 
	{
	 this.className+=" active";
	}
	node.onmouseout=function() 
	{
	 this.className=this.className.replace(" active", "");
	}
   }
  }
 }
}