How to sort this array by date?

I'm trying to sort a array of this kind :

array (
  0 => 
  array (
    'id_ouverture' => 5,
    'debut' => '2011-04-25 08:00:00',
    'fin' => '2011-04-25 20:00:00',
    'id_salle' => 
    array(
       'id' => '7',
       'nom' => 'BLABLA',
       'id_type_salle' => '3',
       'visible' => 1,          
    ),
  ),
  1 => 
  array (
    'id_ouverture' => 6,
    'debut' => '2011-04-18 08:00:00',
    'fin' => '2011-04-18 10:45:00',
    'id_salle' => 
    array(
       'id' => '7',
       'nom' => 'BLABLA',
       'id_type_salle' => '3',
       'visible' => 1,           
    ),
  ),
  2 => 
  array (
    'id_ouverture' => 7,
    'debut' => '2011-05-02 08:00:00',
    'fin' => '2011-05-02 10:45:00',
    'id_salle' => 
    array(
       'id' => '7',
       'nom' => 'BLABLA',
       'id_type_salle' => '3',
       'visible' => 1,
    ),
  ),
  3 => 
  array (
    'id_ouverture' => 8,
    'debut' => '2011-05-09 08:00:00',
    'fin' => '2011-05-09 10:45:00',
    'id_salle' => 
    array(
       'id' => '7',
       'nom' => 'BLABLA',
       'id_type_salle' => '3',
       'visible' => 1,           
    ),
  ));

I need to sort t开发者_如何学Gohis array on this key : array[$i]['debut'] on an ascending order.

The results must be :

array (
  1 => 
  array (
    'id_ouverture' => 6,
    'debut' => '2011-04-18 08:00:00',
    'fin' => '2011-04-18 10:45:00',
    'id_salle' => 
    array(
       'id' => '7',
       'nom' => 'BLABLA',
       'id_type_salle' => '3',
       'visible' => 1,           
    ),
  ),
  0 => 
  array (
    'id_ouverture' => 5,
    'debut' => '2011-04-25 08:00:00',
    'fin' => '2011-04-25 20:00:00',
    'id_salle' => 
    array(
       'id' => '7',
       'nom' => 'BLABLA',
       'id_type_salle' => '3',
       'visible' => 1,          
    ),
  ),

  2 => 
  array (
    'id_ouverture' => 7,
    'debut' => '2011-05-02 08:00:00',
    'fin' => '2011-05-02 10:45:00',
    'id_salle' => 
    array(
       'id' => '7',
       'nom' => 'BLABLA',
       'id_type_salle' => '3',
       'visible' => 1,
    ),
  ),
  3 => 
  array (
    'id_ouverture' => 8,
    'debut' => '2011-05-09 08:00:00',
    'fin' => '2011-05-09 10:45:00',
    'id_salle' => 
    array(
       'id' => '7',
       'nom' => 'BLABLA',
       'id_type_salle' => '3',
       'visible' => 1,           
    ),
  ));

Have you an idea to do it ?

---

You need to use uasort to write a function that will sort the array for you.

http://php.net/manual/en/function.uasort.php

Basically you write your own comparison function and pass it as a callback to the uasort method