<script language="javascript">
<!--
  function funchange(vel)
  {
    document.getElementById(vel).innerText = T1.value;
  }
//-->
</script><input name=T1 size=20><p>
<table>
<tr>
<td id=D1>a1</td>
<td>a2</td>
<td>a3</td>
</tr>
<tr>
<td>b1</td>
<td>b2</td>
<td>b3</td>
</tr>
<tr>
<td>c1</td>
<td>c2</td>
<td>c3</td>
</tr>
</table>
<p><input type=button value=change onclick="funchange('D1');">