JavaScript实现走马灯效果,上 下 左 右无缝连接、循环滚动

<!-- 指向链接图片的URL -->
<div align="center" id="demo" style="overflow:hidden;height:100px;border-width:1px 1px 1px 1px;border-style:dotted dotted dotted dotted;">
    <div id="demo1">
	  <!-- 定义内容-->
	  <a href="#">1 一</a><br>
	  2 二<br>
	  3 三<br>
	  5 四<br>
	  6 五<br>
	  4 六<br>
	  <!-- 定义内容 end-->
    </div>
    <div id="demo2"></div>
</div>

<script language="javascript" type="text/javascript">
<!--
var demo = document.getElementById("demo");
var demo1 = document.getElementById("demo1");
var demo2 = document.getElementById("demo2");
var speed=30;    //数值越大滚动速度越慢
demo2.innerHTML = demo1.innerHTML;

demo.scrollTop = demo.scrollHeight+'px';
function Marquee(){
   /*向下的无缝循环滚动
    if(demo1.offsetTop-demo.scrollTop>=0)
        demo.scrollTop+=demo2.offsetHeight
    else{
        demo.scrollTop--
    }
   */

   /*向下的无缝循环滚动
    if(demo2.offsetTop-demo.scrollTop<=0)    //当滚动至demo1与demo2交界时
        demo.scrollTop-=demo1.offsetHeight    //demo跳到最顶端
    else{
        demo.scrollTop++
	}
	*/
	
	/*向左的无缝循环滚动
	 if(demo2.offsetWidth-demo.scrollLeft<=0)
			demo.scrollLeft-=demo1.offsetWidth
		else{
			demo.scrollLeft++
		}
	*/
	 
	 
	/*向右的无缝循环滚动
	   if(demo.scrollLeft<=0)
			demo.scrollLeft+=demo2.offsetWidth
		else{
			demo.scrollLeft--
		}
	*/
}
var MyMar = setInterval(Marquee,speed);
demo.onmouseover = function(){clearInterval(MyMar)}
demo.onmouseout = function(){MyMar = setInterval(Marquee,speed)}
-->
</script>