js闭包的应用

      <ul id="ul1">
         <li style="border:1px solid red;">1</li>
         <li style="border:1px solid red;">2</li>
         <li style="border:1px solid red;">3</li>
      </ul>

      <div id="div1">
          <div style="background: red;height:300px;display:block;"></div>
          <div style="background: green;height:300px;display:none;"></div>
          <div style="background: blue;height:300px;display:none;"></div>
      </div>

 <a href="http://www.baidu.com" target=“_blank”>link<a>

       window.onload = function(){
              var oLis = document.getElementById("ul1").getElementsByTagName('li');
              for(var i=0; i< oLis.length; i++){
                  oLis[i].onclick = (function(i){
                        return function(){
                          oDiv._change_tab(i);
                       }
                  })(i);
              }
         }

         var oDiv = {
             _change_tab: function(index){
                  var oDivs = document.getElementById("div1").getElementsByTagName("div");
                  var oCur_Slibs = oDiv._get_sliblings(oDivs[index], oDivs);
                  oDivs[index].style.display = "block";
                  for(var n=oCur_Slibs.length-1; n >= 0; n--){
                      oCur_Slibs[n].style.display = "none";
                 }
             },
             _get_sliblings: function(currentNode, childNodes){
                 var slibsList = [];
                 for(var n= childNodes.length-1; n>=0; n--){
                      if(childNodes[n].nodeType === 1 && childNodes[n] !== currentNode){
                           slibsList.push(childNodes[n]);
                      }
                 }
                 return slibsList;
             }
         }

         window.onbeforeunload =  function close(){
             var oLis = document.getElementById("ul1").getElementsByTagName('li');
             for(var n= oLis.length-1; n>=0; n--){
                 oLis[i].onclick = null;
                 console.log(i);
                 alert(i);
             }
         }