请大家帮忙看看下面的代码哪里错了

我想让这些图片从右往左自动循环滚动，可是现在却不动，请大家帮忙看看哪里错了

<div id="marquee" style="overflow:auto;">
<table align=left cellpadding=0 cellspace=0 border=0>
<tr>
<td id=demo1 valign=top><img src="http://images.dangdang.com/images//20099991_m.jpg"><img src="http://images.dangdang.com/images//20102914_m.jpg"><img src="http://images.dangdang.com/images//705244_m.jpg"><img src="http://images.dangdang.com/images//9340298_m.jpg"><img src="http://images.dangdang.com/images//9027867_m.jpg"><img src="http://images.dangdang.com/images//9211875_m.jpg"><img src="http://images.dangdang.com/images//9190819_m.jpg"><img src="http://images.dangdang.com/images//20086549_m.jpg"><img src="http://images.dangdang.com/images//8949555_m.jpg">
</td>
<td id=demo2 valign=top></td>
</tr>
</table>
</div>
<script>
var speed=3
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>

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<div id=demo style="overflow:hidden;width:900;background:#fff;color:#ffffff">
<table align=left cellpadding=0 cellspace=0 border=0>
<tr>
<td id=demo1 valign=top><img src="http://images.dangdang.com/images//20099991_m.jpg"><img
src="http://images.dangdang.com/images//20102914_m.jpg"><img
src="举行悄http://images.dangdang.com/images//705244_m.jpg"><img
src="http://images.dangdang.com/images//9340298_m.jpg"><img
src="http://images.dangdang.com/images//9027867_m.jpg"><img
src="http://images.dangdang.com/images//9211875_m.jpg"><img
src="http://images.dangdang.com/images//9190819_m.jpg"><img
src="http://images.dangdang.com/images//20086549_m.jpg"带激><img
src="http://images.dangdang.com/images//8949555_m.jpg">
</正渣td>
<td id=demo2 valign=top></td>
</tr>
</table>
</div>
<script>
var speed=3
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>

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