var speed=20//速度数值越大速度越慢
document.getElementById("demo2").innerHTML= document.getElementById("demo1").innerHTML
function Marquee(){
if( document.getElementById("demo2").offsetWidth- document.getElementById("demo").scrollLeft<=0)
document.getElementById("demo").scrollLeft-= document.getElementById("demo1").offsetWidth
else{
document.getElementById("demo").scrollLeft++
}
}
var MyMar=setInterval(Marquee,speed)
document.getElementById("demo").onmouseover=function() {clearInterval(MyMar)}
document.getElementById("demo").onmouseout=function() {MyMar=setInterval(Marquee,speed)}