startList = function() 
        {  
            if (document.all&&document.getElementById) 
           {  
               navRoot = document.getElementById("nav");  
                for (i=0; i<navRoot.childNodes.length; i++) 
               {  
                   node = navRoot.childNodes[i];  
                   if (node.nodeName=="LI") 
                   {  
                       node.onmouseover=function() 
                       {  
                           this.className+="on";   
                       }   
                       node.onmouseout=function() 
                       {  
                           this.className=this.className.replace("on", "");   
                       }                       
                   }  
               }  
           }  
       }  
       window.onload=startList;