js文字无缝滚动

 <div id=demo style="overflow:hidden; width:128px; height:300px;">
 <div id=demo1>
   <table width="90%" cellspacing="" cellpadding="" border="" align="center"><tbody><tr><td class="ykxm">孙君洲&nbsp;</td><td>1人</td><td>&nbsp;--06到</td><td class="xdd"><font color="#FF0000">新订单</font></td></tr><tr><td class="ykxm">冀先生&nbsp;</td><td>12人</td><td>&nbsp;--25到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">李璐婵&nbsp;</td><td>3人</td><td>&nbsp;--10到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">徐澜&nbsp;</td><td>2人</td><td>&nbsp;--26到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">周益毅&nbsp;</td><td>2人</td><td>&nbsp;--27到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">林思颖&nbsp;</td><td>2人</td><td>&nbsp;--24到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">赵志礼&nbsp;</td><td>3人</td><td>&nbsp;--30到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">郑朝海&nbsp;</td><td>3人</td><td>&nbsp;--22到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">黄生&nbsp;</td><td>3人</td><td>&nbsp;--22到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">蒲先生&nbsp;</td><td>5人</td><td>&nbsp;--01到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">杨虞&nbsp;</td><td>4人</td><td>&nbsp;--22到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr><tr><td class="ykxm">恽小姐&nbsp;</td><td>3人</td><td>&nbsp;--21到</td><td class="ycldd"><font color="#009900">已确认</font></td></tr></tbody></table>
 </div>
 <div id=demo2></div>
 </div>
 <script language="javascript">
 var speed=
 demo2.innerHTML=demo1.innerHTML
 function Marquee(){
 if(demo2.offsetTop-demo.scrollTop<=)
 demo.scrollTop-=demo1.offsetHeight
 else{
 demo.scrollTop++
 }
 }
 var MyMar=setInterval(Marquee,speed)
 demo.onmouseover=function() {clearInterval(MyMar)}
 demo.onmouseout=function() {MyMar=setInterval(Marquee,speed)}
 </script>