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+=" over";  
     }  
     node.onmouseout=function() {  
     this.className=this.className.replace(" over", "");  
      }  
      }  
     }  
    }  
   }  
   window.onload=startList;