/*firefox----这段js重新封装了event对象，经验证可以在火狐下支持！----*/

    function __firefox(){

        HTMLElement.prototype.__defineGetter__("runtimeStyle", __element_style);

        window.constructor.prototype.__defineGetter__("event", __window_event);

        Event.prototype.__defineGetter__("srcElement", __event_srcElement);

    }

    function __element_style(){

        return this.style;

    }

    function __window_event(){

        return __window_event_constructor();

    }

    function __event_srcElement(){

        return this.target;

    }

    function __window_event_constructor(){

        if(document.all){

            return window.event;

        }

        var _caller = __window_event_constructor.caller;

        while(_caller!=null){

            var _argument = _caller.arguments[0];

            if(_argument){

                var _temp = _argument.constructor;

                if(_temp.toString().indexOf("Event")!=-1){

                    return _argument;

                }

            }

            _caller = _caller.caller;

        }

        return null;

    }

    if(window.addEventListener){

        __firefox();

    }

    /*end firefox------------------------------------------------*/