var bindEvent = {

    'add':function(id,type,fn,isBubble){

      var dom = document.getElementById(id);
      if(!isBubble) isBubble=false;
      if(dom.addEventListenner){
        dom.addEventListenner(type,fn,isBubble);
      }else if(dom.attachEvent){
        Transit = function(){
          fn.call(dom);
        }
        dom.attachEvent('on'+type,Transit);
      }else{
        dom['on'+type] = fn;
      }
    },
    'remove':function(id,type,fn,isBubble){
      var dom = document.getElementById(id);
      if(!isBubble) isBubble=false;
      if(dom.removeEventListenner){
        dom.removeEventListenner(type,fn,isBubble)
      }else if(dom.detachEvent){
        dom.detachEvent('on'+type,Transit)
      }else{
        dom['on'+type]=null;
      }

    }

  }

//定义事件处理程序
 function msg(){
  alert(this.tagName)
 }

 //为目标元素绑定事件
 bindEvent.add('link','click',msg,false);

 //解除目标元素绑定的事件
 bindEvent.remove('link','click',msg,false);