var MyMar=null;
function MarqueeLeft()
{
    if(document.getElementById("demo2").offsetWidth-document.getElementById("demo").scrollLeft<=0)
        document.getElementById("demo").scrollLeft-=document.getElementById("demo1").offsetWidth;
    else
    {
        document.getElementById("demo").scrollLeft++;
    }
}
function MarqueeRight()
{
    if(document.getElementById("demo").scrollLeft<=0)
        document.getElementById("demo").scrollLeft+=document.getElementById("demo2").offsetWidth;
    else
    {
        document.getElementById("demo").scrollLeft--;
    }
}
function myMarquee(d,s)
{
    //速度,数值越大越慢
    if(MyMar !=null)
    {
        clearInterval(MyMar);
    }
    MyMar=setInterval(d,s);
    document.getElementById("demo").onmouseover=function() {clearInterval(MyMar);};
    document.getElementById("demo").onmouseout=function() {MyMar=setInterval(d,s);};
}
function init()
{
    document.getElementById("demo2").innerHTML=document.getElementById("demo1").innerHTML;
    myMarquee(MarqueeLeft,10);
}