图片从右往左无间隙滚动代码

<div class="rollBox" id="demo" style="overflow:hidden; height:77px; 700px; color:#ffffff; ">
<table width="100%" border="0" align="center" cellpadding="0" cellspacing="0">
<tr align="center">
<td id="demo1">
<table border="0" align="center" cellpadding="6px" cellspacing="0">
<tr>
<td align="center">
 <a href="show.aspx?id=67&cid=21" target="_blank"><img src="image/old1.jpg" alt="" width="150" height="80" /></a>
 </td>
 <td> <a href="show.aspx?id=68&cid=21" target="_blank"><img src="image/old2.jpg" alt="" width="150" height="80" /></a></td>
  <td> <a href="show.aspx?id=69&cid=21" target="_blank"><img src="image/old3.jpg" alt="" width="150" height="80" /></a></td>
   <td> <a href="show.aspx?id=70&cid=21" target="_blank"><img src="image/old4.jpg" alt="" width="150" height="80" /></a></td>
    <td> <a href="show.aspx?id=71&cid=21" target="_blank"><img src="image/old5.jpg" alt="" width="150" height="80" /></a></td>
</tr>
</table>
</td>
<td id="demo2"></td>
</tr>
</table>
</div>
 
<SCRIPT language="javascript" defer>
function GetObj(objName)
{
 if(document.getElementById)
 {
  return eval('document.getElementById("'+objName+'")');
 }
 else
 {
  return eval('document.all.'+objName);
 }
}
 
var rollSpeed = 15;//速度数值越大速度越慢
var rollStep  = 1; //滚动步长
var rollLeft  = true; //往左滚动
 
GetObj("demo2").innerHTML=GetObj("demo1").innerHTML;
 
function Marquee()
{
    if(rollLeft)
 {
  if(GetObj("demo").scrollLeft>=GetObj("demo1").offsetWidth)
  {
   GetObj("demo").scrollLeft-=GetObj("demo1").offsetWidth;
  }
  else
  {
   GetObj("demo").scrollLeft+=rollStep;
  }
 }
 else
 {
  if(GetObj("demo").scrollLeft<=0)
  {
   GetObj("demo").scrollLeft+=GetObj("demo1").offsetWidth;
  }
  else
  {
   GetObj("demo").scrollLeft-=rollStep;
  }
 }
}
 
function MarqueeLeft_ON()
{
    rollLeft = true;
 rollStep = 20;
}
 
function MarqueeLeft_OFF()
{
    rollStep = 1;
}
 
function MarqueeRight_ON()
{
    rollLeft = false;
 rollStep = 20;
}
 
function MarqueeRight_OFF()
{
    rollStep = 1;
}
 
var MyMar=setInterval(Marquee,rollSpeed);
GetObj("demo").onmouseover=function() {clearInterval(MyMar);}
GetObj("demo").onmouseout=function() {MyMar=setInterval(Marquee,rollSpeed);}
</SCRIPT>