function is_allowed()
{
  global $user;
  $idgroups_user = array();
  $idgroups = array();
  $query = 'SELECT group_id FROM ' . USER_GROUP_TABLE . ' WHERE user_id = ' . $user['id'] . ';';
  $result = pwg_query($query);
  while ($row = mysql_fetch_assoc($result))
  {
    array_push($idgroups_user, $row['group_id']);
  }
  $query = 'SELECT id FROM ' . GROUPS_TABLE . ' WHERE name IN (\'ééééé_\', \'groupe1\') ORDER BY id';
  $result = pwg_query($query);
  while ($row = mysql_fetch_assoc($result))
  {
    array_push($idgroups, $row['id']);
  }
  if (empty($idgroups)) return false;
  foreach( $idgroups as $id )
  {
    if ( in_array($id, $idgroups_user))
    {
      return true;
      exit; 
    }
  }
  return false;
}