function _marquee(box, block1, block2, sp){

		var speed = sp;

		var marqueeInterval;

		var nuliBox = document.getElementById(box);

		var nuli1=document.getElementById(block1);

		var nuli2=document.getElementById(block2);

		nuli2.innerHTML=nuli1.innerHTML; //克隆

		marqueeInterval = setInterval(function() {_scrollMarquee(box, block1, block2);},speed);

		//开始滚动

		nuliBox.onmouseout = function (){marqueeInterval = setInterval(function() {_scrollMarquee(box, block1, block2);},speed);}

		//停止滚动

		nuliBox.onmouseover = function (){clearInterval(marqueeInterval);}

	}

	

	//实现滚动效果

	function _scrollMarquee(box, block1, block2){

		var nuliBox = document.getElementById(box);

		var nuli1=document.getElementById(block1);

		var nuli2=document.getElementById(block2);

		if(nuliBox.scrollTop>=0){

		nuliBox.scrollTop++;

		if(nuliBox.scrollTop >= nuli2.offsetHeight){

			 nuliBox.scrollTop = 0;

		 }

		} 

	}