无缝上下滚动

<table width="84%" border="0" align="center" cellpadding="0" cellspacing="0"  >
                            <tr>
                              <td><img src="images/quanyunhui_009.JPG" width="193" height="30"></td>
                            </tr>
                            <tr>
                              <td height="192"><table width="89%" border="0" align="center" cellpadding="0" cellspacing="0" class="style2" >
                                  <tr>
                                    <td height="300"  valign="top">
         <div id=marquees height=200 style="POSITION: absolute;overflow:auto;">
     <table  border="0" cellpadding="0" cellspacing="0">
     <tr>
                <td width="250" height="25">aaaaaaaaaad</td>
              </tr>
     <tr>
                <td width="250" height="25">ddddddddddddd</td>
              </tr>
     <tr>
                <td width="250" height="25">ddddddddddddd</td>
              </tr>
     <tr>
                <td width="250" height="25">ddddddddddddd</td>
              </tr>
                </table></div>    
    <script language="JavaScript">
     marqueesHeight=300;
     stopscroll=false;

     with(marquees){
      style.width=0;
      style.height=marqueesHeight;
      style.overflowX="visible";
      style.overflowY="hidden";
      noWrap=true;
      οnmοuseοver=new Function("stopscroll=true");
      οnmοuseοut=new Function("stopscroll=false");
     }
     document.write('<div id="templayer" style="position:absolute;z-index:1;visibility:hidden"></div>');

     preTop=0; currentTop=0;

     function init(){
      templayer.innerHTML="";
      while(templayer.offsetHeight<marqueesHeight){
       templayer.innerHTML+=marquees.innerHTML;
      }
      marquees.innerHTML=templayer.innerHTML+templayer.innerHTML;
      setInterval("scrollup()",100);
     }
     document.body.οnlοad=init;

     function scrollup(){
      if(stopscroll==true) return;
      preTop=marquees.scrollTop;
      marquees.scrollTop+=1;
      if(preTop==marquees.scrollTop){
       marquees.scrollTop=templayer.offsetHeight-marqueesHeight;
       marquees.scrollTop+=1;
      }
     }
    </script></td>
                                  </tr>
                              </table></td>
                            </tr>
                            <tr>
                                        
                            </tr>
                           
                        </table>