/**
   *
   * @param array $errors : optional assign it to
   * @param string $target : url for redirect of the request
   */
  protected function forwardRequest(array $errors = null, $target = null) {
    //check for given target and try to fall back to previous page if needed
    if ($target == null) {
      if (!isset($_REQUEST[self::PAGE])) {
        throw new Exception('Missing target for forward.');
      }
      $target = $_REQUEST[self::PAGE];
    }
    //forward request to target
    // optional - add errors to redirect and process them in view
    if (count($errors) > 0)
      $target .= '&errors=' . urlencode(serialize($errors));
    header('location: ' . $target);
    exit();
  }