var speed=40;//数值越大，速度越慢
var demo2=document.getElementById("demo2");
var demo1=document.getElementById("demo1");
var demo=document.getElementById("demo");
demo2.innerHTML=demo1.innerHTML;
demo.scrollTop=demo.scrollHeight;
function MarqueeUp(){
if(demo2.offsetTop-demo.scrollTop<=0){
demo.scrollTop-=demo2.offsetHeight;
}else{
demo.scrollTop++;
}
}
var MyMar=setInterval(MarqueeUp,speed);
demo.onmouseover=function() {clearInterval(MyMar);}
demo.onmouseout=function() {MyMar=setInterval(MarqueeUp,speed);}