var demo = document.getElementById("demo");
var demo1 = document.getElementById("demo1");
var demo2 = document.getElementById("demo2");
var speed=50;    
demo2.innerHTML = demo1.innerHTML    
function Marquee(){
   if(demo1.offsetTop-demo.scrollTop>=0)
        demo.scrollTop+=demo2.offsetHeight
    else{
        demo.scrollTop--
    }
}
var MyMar = setInterval(Marquee,speed);        
demo.onmouseover = function(){clearInterval(MyMar)}    
demo.onmouseout = function(){MyMar = setInterval(Marquee,speed)}