// JavaScript Document
 var Marquee = function(id) {
            try { document.execCommand("BackgroundImageCache", false, true); } catch (e) { };
            var container = document.getElementById(id),
            original = container.getElementsByTagName("dt")[0],
            clone = container.getElementsByTagName("dd")[0],
            speed = arguments[1] || 10;
            clone.innerHTML = original.innerHTML;

            var rolling = function() {
                if (container.scrollLeft == clone.offsetLeft) {
                    container.scrollLeft = 0;
                } else {
                    container.scrollLeft++;
                }
            }
            var timer = setInterval(rolling, speed)//设置定时器
            container.onmouseover = function() { clearInterval(timer) } //鼠标移到marquee上时，清除定时器，停止滚动
            container.onmouseout = function() { timer = setInterval(rolling, speed) } //鼠标移开时重设定时器
        }
        window.onload = function() {
            Marquee("marquee");
        }