var speed = 15;//滚动速度
var rows = 28;//每行高度
var stim = 80; //停留时间倍数 * speed
var stop = 0; //初始化值，不管
demo2.innerHTML = demo1.innerHTML
function Marquee(){
    if(demo.scrollTop%rows==0 && stop<=stim){
      stop++;
      return;
    }
    stop = 0;
    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)}