<table width="99%" border="0" align="center" cellpadding="0" cellspacing="1" bgcolor="#FFFFFF">
              <tr align="center" bgcolor="#66CCFF"> 
                <td><font color="#FFFFFF"><a href="javascript:showimg('img1');">第1金</a></font></td>
                <td><font color="#FFFFFF"><a onclick="javascript:showimg('img2');">第2金</a></font></td>
                <td><font color="#FFFFFF"><a onclick="javascript:showimg('img3');">第3金</a></font></td>
                <td><font color="#FFFFFF"><a onclick="javascript:showimg('img4');">第4金</a></font></td>
                <td><font color="#FFFFFF"><a onclick="javascript:showimg('img5');">第5金</a></font></td></tr> </table>
<img id="imgid">
<script language="javascript">
function showimg(id){
document.imgid.src=id+".jpg"

</script>试一试