循环不间断显示滚动图片

<div id="demo" style="OVERFLOW:hidden;WIDTH:800px;COLOR:#ffffff">
                                <table cellpadding="0" cellspacing="0" border="0">
                                    <tr>
                                        <td id="demo1" valign="top" align="center">
                                            <table cellpadding="2" cellspacing="0" border="0">
                                                <tr align="center">
                                                    <td>
   图片地址
</td>
                                                </tr>
                                            </table>
                                        </td>
                                        <td id="demo2" valign="top"></td>
                                    </tr>
                                </table>
                            </div>
                            <script>
                                var speed=2//速度数值越大速度越慢
                                demo2.innerHTML=demo1.innerHTML
                                function Marquee(){
                                if(demo2.offsetWidth-demo.scrollLeft<=0)
                                demo.scrollLeft-=demo1.offsetWidth
                                else{
                                demo.scrollLeft++
                                }
                                }
                                var MyMar=setInterval(Marquee,speed)
                                demo.onmouseover=function() {clearInterval(MyMar)}
                                demo.onmouseout=function() {MyMar=setInterval(Marquee,speed)}
                            </script>