当鼠标放到向上向下图片时，让<table>滚动

<%@ page contentType="text/html; charset=gb2312" import=" com.dhcc.sso.SsoConst" language="java" %>
谢谢，给down-down.gif和up-up.gif添加鼠标事件，当鼠标放上去后，制定table滚动，谢谢
<script type="text/javascript">
function myroll()
   {   
    document.write('<marquee scrollAmount=2 width=340 height=160 direction=up onmouseover=stop() onmouseout=start()>2222222222</marquee>');
    }
</script><%
    Object userid = session.getAttribute("userid");    String oahref = "http://oa.sgqg.com:8089";
    if((userid!=null)&&(!userid.equals("")))
    {
       //判断能否取道cookie
       Cookie[] cooks = request.getCookies();
       String ssoCookName = SsoConst.SsoToken;       for(int i=0;i<cooks.length;i++)
       {
          String cookName = cooks[i].getName();
          if(cookName.equals(ssoCookName)) //从cookie获取到了另派串
          {
             oahref = "http://oa.sgqg.com:8089/login.do";
             break;
          }
       }
    }
%>
<table width="211" border="0" align="center" cellpadding="0" cellspacing="0">
  <tr>
    <td align="right"><img src="images/up-up.gif" border="0" ></td>
    <td align="left"><img src="images/down-down.gif" border="0" ></td>
  </tr>
</table>
<table border="0" align="center" cellpadding="0" class="sy_kstd">
<tr>
<td width="45" align="center">
            <img src="images/ico/A01.gif" width="36" height="36"/>
        </td>
<td align="center">
            <a target='_blank' href="<%=oahref%>" class="sy_kstd_text">办公自动化系统</a>
        </td>
</tr>
</table>
<table border="0" align="center" cellpadding="0" class="sy_kstd">
    <tr>
<td width="45" align="center">
<img src="images/ico/A03.gif" width="36" height="36"/></td>
<td align="center"><a href="#" class="sy_kstd_text">一卡通系统</a></td>
</tr>
</table>
<table  border="0" align="center" cellpadding="0" class="sy_kstd">
  <tr>
    <td width="45" align="center">
<img src="../images/ico/A14.gif" width="36" height="36"/></td>
    <td  align="center">
<a href="http://10.3.250.243:8080/qgmrp/" class="sy_kstd_text">材料供应系统</a></td>
  </tr>
</table>
<table width="150" border="0" align="center" cellpadding="0" class="sy_kstd">
  <tr>
    <td width="45" align="center"><img src="../images/ico/A08.gif" width="36" height="36"/></td>
    <td  align="center">
<a href="http://10.3.79.43:8080/e_/" class="sy_kstd_text">年度绩效评测系统</a></td>
  </tr>
</table>
<table border="0" align="center" cellpadding="0" class="sy_kstd">
  <tr>
    <td width="45" align="center"><img src="../images/ico/A14.gif" width="36" height="36"/></td>
    <td align="center"><a href="http://10.3.250.238:8080/qgdj/" class="sy_kstd_text">设备管理系统</a></td>
  </tr>
</table>
<table border="0" align="center" cellpadding="0" class="sy_kstd">
  <tr>
    <td width="45" align="center"><img src="../images/ico/A10.gif" width="36" height="36"/></td>
    <td  align="center"><a href="http://10.3.250.245:8080/wzjl/" class="sy_kstd_text">物资计量系统</a></td>
  </tr>
</table>
<table border="0" align="center" cellpadding="0" class="sy_kstd">
  <tr>
    <td width="45" align="center"><img src="../images/ico/A16.gif" width="36" height="36"/></td>
    <td  align="center"><a href="http://10.3.250.240/vod/usrlogin.jsp" class="sy_kstd_text">视频教育系统</a></td>
  </tr>
</table>
<table border="0" align="center" cellpadding="0" class="sy_kstd">
    <tr>
<td width="45" align="center">
<img src="images/ico/A12.gif" width="36" height="36"/></td>
<td align="center">
            <a href="http://www.sgpx.com.cn/sgstudyonline/MainPage/BlockIntro.aspx?blockkey=6e72c835-7518-4b97-98df-dafc2a7b111c" class="sy_kstd_text">
                数字图书馆
            </a>
       </td>
</tr>
</table>
<table border="0" align="center" cellpadding="0" class="sy_kstd">
    <tr>
<td width="45" align="center">
<img src="images/ico/A08.gif" width="36" height="36"/></td>
<td align="center"><a href="http://mail.sgqg.com/" class="sy_kstd_text">公司邮箱</a></td>
</tr>
</table>
<script>
   function logout()
   {
    alert('this a ');
   }
   window.onclose="logout()";
</script>