跨浏览器的事件对象代码

var Event = {
   addHandler : function(element, type, handler) {
         if (element.addEventListener) {
                 element.addEventListener(type, handler, false);
         } else if (element.attachEvent) {
                 element.attachEvent("on" + type, handler);
         } else {
                 element["on" + type] = handler;
         }
    },
   removeHandler : function(element, type, handler) {
         if (element.removeEventListener) {
                element.removeEventListener(type, handler, false);
         } else if (element.detachEvent) {
               element.detachEvent("on" + type, handler);
         } else {
               element["on" + type] = null;
         }
    },
   getEvent : function(event) {
         return event ? event : window.event;
   },
   getTarget : function(event) {
        return event.target || event.srcElement;
   },
   preventDefault : function(event) {
       if (event.preventDefault) {
              event.preventDefault();
       } else {
              event.returnValue = false;
       }
    },
   stopPropagation : function(event) {
       if (event.stopPropagation) {
              event.stopPropagation();
       } else {
             event.cancelBubble = true;
       }
    }
};