var speed = 30;

marquePic2.innerHTML = document.getElementById("marquePic1").innerHTML;
function Marquee() {
    if (demo.scrollLeft >= marquePic1.scrollWidth) {
        demo.scrollLeft = 0
    } else {
    demo.scrollLeft++;
    }
}
var MyMar = setInterval(Marquee, speed);
demo.onmouseover = function() { clearInterval(MyMar); }
demo.onmouseout = function() { MyMar = setInterval(Marquee, speed); }