Asp.net datalist 图片连续循环滚动 不出现空白 问题解决

<div id="ProductsShowInFPBody">
  <div id="demo"  style ="width:1000px;height:220px; overflow :hidden "> 
     <table >  

        <tr>
           <td>
             <div id="demo1" >                                                            
                <asp:DataList ID="dstProduct"runat="server" DataSourceID="odsproduct"             RepeatDirection="Horizontal">
                    <ItemTemplate>
                      <div id="ProductItem">
                           <div id="ProductPic">
                             <img src ="Pic/ProductPic/<%# eval_r("PicUrl") %>" alt="暂无图" title ="" class="ProductPic"  /> 
                            </div> 
                      </div>                                                             
                    </ItemTemplate>
                 </asp:DataList>         
              </div> 
             </td>
           <td>
             <div id="demo2"  >
              </div> 
                                
             </td>
         </tr>
     </table>
</div>  

<script type="text/javascript">
            var speed=10;  //设置图片滚动速度
            demo2.innerHTML=demo1.innerHTML  //复制demo1为demo2
            function Marquee(){
                if(demo2.offsetWidth-demo.scrollLeft<=0)   //当滚动至demo1与demo2交界时
                  
                    demo.scrollLeft-=demo1.offsetWidth     //dome跳到最左端
                else{
                    demo.scrollLeft++
                }
            }
            var MyMar=window.setInterval(Marquee,speed)  //设置定时器
            demo.onmouseover=function () {clearInterval(MyMar)}  //鼠标移上时清除定时器达到滚动停止的目的
            demo.onmouseout=function () {MyMar=setInterval(Marquee,speed)}//鼠标移开时重设定时器，继续滚动
      </script>