兼容firefox，ie，谷歌，阻止浏览器冒泡事件，Firefox不支持event解决方法

 //        获取事件
function getEvent(){

    if(window.event)    {return window.event;}

    func=getEvent.caller;
    while(func!=null){

        var arg0=func.arguments[0];
        if(arg0){

            if((arg0.constructor==Event || arg0.constructor ==MouseEvent
                || arg0.constructor==KeyboardEvent)

                ||(typeof(arg0)=="object" && arg0.preventDefault
                && arg0.stopPropagation)){

                return arg0;
            }

        }

        func=func.caller;
    }

    return null;
}

//阻止冒泡
function cancelBubble()

{

    var e=getEvent();
    if(window.event){

        //e.returnValue=false;//阻止自身行为
        e.cancelBubble=true;//阻止冒泡
    }else if(e.preventDefault){

        //e.preventDefault();//阻止自身行为
        e.stopPropagation();//阻止冒泡
    }

}