var speed4=25//速度数值越大速度越慢
dm2.innerHTML=dm1.innerHTML
function Marquee2(){
if(dm2.offsetHeight-dm.scrollTop<=0)
dm.scrollTop-=dm1.offsetHeight
else{
dm.scrollTop++
}
}
var LogoMar=setInterval(Marquee2,speed4)
dm.onmouseover=function() {clearInterval(LogoMar)}
dm.onmouseout=function() {LogoMar=setInterval(Marquee2,speed4)}