public function _submit()
 {
     $f = $_POST;
     $app = new WoodwindApply($f);
     list($required, $filled, $percent) = $app->progress();
     $_SESSION['woodwind-day']['f'] = $app->form();
     if ($percent < 1) {
         $_SESSION['errors'][] = 'Please fill in all required fields.';
         PSU::redirect($GLOBALS['BASE_URL'] . '/register');
     }
     if ($id = $app->save()) {
         WoodwindAPI::mail($id);
     } else {
         $_SESSION['errors'][] = 'There was an error saving your submission data.';
         PSU::redirect($GLOBALS['BASE_URL'] . '/register');
     }
     PSU::redirect($GLOBALS['BASE_URL'] . '/thank-you');
 }