跨浏览器的事件对象

var EventUtil = {

   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;

};