// Méthode hashage du mot de passe.
if (function_exists('sha1'))  // Only in PHP 4.3.0+
{
    $password = sha1($_POST['use_new_pwd']);
}
else if (function_exists('mhash'))  // Only if Mhash library is loaded
{
    $password =  bin2hex(mhash(MHASH_SHA1, $_POST['use_new_pwd']));
}
else
{
    $password =  md5($_POST['use_new_pwd']);
}

// Selection de l'id utilisateur dans punBB
$query = '
        SELECT id_user_punbb
        FROM '.MOD_REGISTER_PUNBB_ID
        .' WHERE id_user_pwg = '.$userdata['id'].';
    ';
$result = pwg_query($query);

=> while($row = mysql_fetch_array($result)) <=
{
    // Modification du mail
    $query = '
            UPDATE '.$conf['punbb_prefix'].'users 
            SET email = \''.$_POST['mail_address'].'\'';

            // Si le champs nouveau mot de passe n'est pas vide
            // alors on insert la modification dans la table
            // users de PunBB en hashant le mot de passe.
            if (!empty($_POST['use_new_pwd']))
            {
                $query.= ', password = \''.$password.'\'';
            }
            $query.= ' WHERE id = '.$row['id_user_punbb'].';
        ';
    $result = pwg_query($query);
}