var speed=20; //数字越大速度越慢
    var taba=document.getElementById("Demohj");
    var taba1=document.getElementById("Demohj1");
    var taba2=document.getElementById("Demohj2");
    taba2.innerHTML=taba1.innerHTML;
    function Marquee(){
    if(taba2.offsetWidth-taba.scrollLeft<=0)
    taba.scrollLeft-=taba1.offsetWidth
    else{
    taba.scrollLeft++;
    }
    }
    var MyMar=setInterval(Marquee,speed);
    taba.onmouseover=function() {clearInterval(MyMar)};
    taba.onmouseout=function() {MyMar=setInterval(Marquee,speed)};