var speed=20
  demo2.innerHTML=demo1.innerHTML
  function Marquee(){
  if(demo2.offsetHeight-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)}