201507231056_《JavaScript——事件脚本的添加和删除代码》

funtion addHangler(target,eventType,Handler) {
    if(target.addEventListener){
       target.addEventListener(eventType,handler,false);
  }else{
       target.attachEvent("on" + eventType , handler);
  }
}

funtion removeHangler(target,eventType,Handler) {
    if(target.removeEventListener){
      target.removeEventListener(eventType,handler,false);
  }else{
       target.detachEvent("on" + eventType , handler);
  }
}

还有一种预加载技术，适合在全局，在经常用到的场合

 var addHandler = document.body.addEventListener ? 
  function(target, eventType, handler){ 
    target.addEventListener(eventType, handler, false); 
  }: 
  function(target, eventType, handler){ 
    target.attachEvent("on" + eventType, handler); 
  }; 




var removeHandler = document.body.removeEventListener ? 
  function(target, eventType, handler){ 
    target.removeEventListener(eventType, handler, false); 
  }: 
  function(target, eventType, handler){ 
    target.detachEvent("on" + eventType, handler); 
  };