[javascript] Add/delete row from a table

JavaScript with a few modifications:

function deleteRow(btn) {
  var row = btn.parentNode.parentNode;
  row.parentNode.removeChild(row);
}

And the HTML with a little difference:

<table id="dsTable">
  <tbody>
    <tr>
      <td>Relationship Type</td>
      <td>Date of Birth</td>
      <td>Gender</td>
    </tr>
    <tr>
      <td>Spouse</td>
      <td>1980-22-03</td>
      <td>female</td>
      <td><input type="button" value="Add" onclick="add()"/></td>
      <td><input type="button" value="Delete" onclick="deleteRow(this)"/></td>
    </tr>
    <tr>
      <td>Child</td>
      <td>2008-23-06</td>
      <td>female</td>
      <td><input type="button" value="Add" onclick="add()"/></td>
      <td><input type="button" value="Delete" onclick="deleteRow(this)"/></td>
    </tr>
  </tbody>
</table>???????????????????????????????????