javascript: getting td index

Possible Duplicate:
Table row and column number in jQuery

If I have a table like so:

<table>
  <thead>
     <tr><th>1</th> <th>2</th> <th>3</th></tr>
  </thead>

  <tbody>
    <tr><td>data</td> <td>checkbox</td> <td>data</td></tr>
  </tbody>
</table>

When the user clicks the checkbox, I want to get the row and column indices. I can get the row index by using this code:

 var row = $(this).parent().parent();
 var rowIndex = $(row[0].rowIndex);

but I can't figure out the column index...

I tried this but it didn't work:

 var colIndex = $(row.children().index(this).parent());

I looked through the results of similar questions here and it seems I have to iterate through all the tds with each or map, is there something simpler that I can use? Thanks.