javascribe中文字滚动出现一些问题

Question

var speed=50
demo2.innerHTML=demo1.innerHTML
//demo3.innerHTML=demo1.innerHTML
//demo4.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)}
滚动了两次就停止，这怎么破啊~~请各位大侠们指教？？？

Answer 1

Marquee()里面要加这个
setInterval(Marquee,speed)