<script>
function getID(oObject)
{
var id = oObject.id;
alert("This object's ID attribute is set to \"" + id + "\".");
}
</script>
<table border="">
<tr>
<td id="firstCell" >Table Cell 1</td>
<td id="secondCell" >Table Cell 2</td>
<td id="thirdCell" >Table Cell 3</td>
</tr>
</table>