[jQuery] Excluding some children in a selector

[Thierry]

I have the following structure for tr:

<tr id="world">
   <td></td>
   <td></td>
   <td>
      <input type="button" name="hello" value="hello" />
   </td>
</tr>

I also have the following javascript:

$("#world tr").click(function() {
   // do stuffs
});

Is there a way to prevent the above event from triggering when the
hello button is clicked?