js文字无缝滚动

<div id=demo style="overflow:hidden; 128px; height:300px;"> 
<div id=demo1> 
  <table width="90%" cellspacing="3" cellpadding="0" border="0" align="center"><tbody><tr><td class="ykxm">孙君洲&nbsp;</td><td>1人</td><td>&nbsp;2013-09-06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;2013-08-25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;2013-09-10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;2013-08-26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;2013-08-27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;2013-08-24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;2013-08-30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;2013-08-22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;2013-08-22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;2014-08-01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;2013-09-22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;2014-06-21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=30 
demo2.innerHTML=demo1.innerHTML 
function Marquee(){ 
if(demo2.offsetTop-demo.scrollTop<=0) 
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>