<html xmlns="http://www.w3.org/1999/xhtml">
<head>

<script>

function boom()
{
  document.getElementById('A').setAttribute('colspan', 0);
  document.getElementById('B').setAttribute('rowspan', 3);
}

</script>

</head>

<body onload="boom();">

<table>
  <tr>
    <td id="A">TD</td>
    <td id="B" colspan="3">TD</td>
  </tr>
</table>

</body>
</html>