js 阻止事件冒泡 支持所有主流浏览器

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;
}
//阻止事件冒泡
function stopEvent(){
	try{
		(window.event.cancelBubble = true)
	}catch(e){
		getEvent().stopPropagation()
	}
}