var speed=30  
demo2.innerHTML=demo1.innerHTML  
function Marquee(){  
if(demo2.offsetTop-demo.scrollTop<=0)  
demo.scrollTop-=demo1.offsetHeight  
else{  
demo.scrollTop++  
}  
}  
var MyMar=setInterval(Marquee,speed)  
demo.onmouseover=function() {clearInterval(MyMar)}  
demo.onmouseout=function() {MyMar=setInterval(Marquee,speed)}