var Bind = function (obj,fun,Class){return function() {return fun.call(obj,Class)}};
function tab(id,type){
  var nav = document.getElementById(id).getElementsByTagName("ul")[0].childNodes;
  var _nav = nav[0];
  while(_nav){
   if(_nav.className=="sel")this.checked = _nav;
   if(_nav.childNodes.length>1){
     _nav.getElementsByTagName("A")[0]["on"+type] = Bind(_nav,fun,this);
   }
   _nav = _nav.nextSibling;
  }
  function fun(Class){
   if(this.className=="sel")return;
   this.getElementsByTagName("A")[0].blur();
   this.className="sel";
   Class.checked.className="";
   Class.checked = this;
  };
}