startList = function() 
{
     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;