function Roll(obj,obj1,speed,stopPx){  //几个参数的含义是, 外框的名字, 中间放内容的DIV的名字, 滚动动的速度, 每多少象素停一下 
	if (speed==null){speed=30}
	if (stopPx==null){stopPx=100}
	
	obj=document.getElementById(obj);
	obj1=document.getElementById(obj1);
	obj.style.overflow="hidden";
	
	var tObj=document.createElement("div")
	obj2=obj.appendChild(tObj);
	obj2.style.cssText=obj1.style.cssText;
	obj2.className=obj1.className;
	obj2.innerHTML=obj1.innerHTML;
	var movePx=0;
	var MyMar;
	var stopTime=4000; //改这里可以改停留的时间, 现在设置的是4秒, 
	
	function Marquee()
	{
	 movePx++;
	 if (movePx>stopPx){
	 	movePx=0;
		clearInterval(MyMar);
		rollNext();
	 	return;
	 }
	 if(obj2.offsetTop-obj.scrollTop<=0)
	  obj.scrollTop-=obj1.offsetHeight;
	 else
	  obj.scrollTop++;
	}
		
	function rollNext(){
		setTimeout(start,stopTime);  
	}
	
	function start(){
		MyMar=setInterval(Marquee,speed)
	}
	setTimeout(start,stopTime);
}