​x
 
<html>
<head>
<script type="text/javascript">
function alignText()
{
document.getElementById("td1").style.verticalAlign="bottom";
}
</script>
</head>
<body>
​
<table border="1" height="100px">
  <tr>
    <td id="td1">
    Some example text
    </td> 
  </tr>
</table>
<br />
<input type="button" onclick="alignText()" value="Align text" />
​
</body>
</html>
​