PHP AJAX Function

/***************************************
 *	 Formular zum bearbeiten eines Fahrschülers anzeigen
 ***************************************/
function fahrapp_show_user_edit_form() {
	$driver_id = esc_attr( $_POST['driver_id'] );
	if(!check_teacher_has_right_to_driver($driver_id)):
		echo 'Ihnen fehlt die Berechtigung um dieses Fahrschüler zu bearbeiten.';
		exit();
	endif;
	$form_id = get_field('setform_driver_edit', 'option');
	$firstname = get_field('driver_firstname', $driver_id);
	$lastname = get_field('driver_lastname', $driver_id);
	$gender = get_field('driver_gender', $driver_id);
	$job = get_field('driver_job', $driver_id);
	$streetnr = get_field('driver_streetnr', $driver_id);
	$plz = get_field('driver_plz', $driver_id);
	$ort = get_field('driver_ort', $driver_id);
	$country = get_field('driver_country', $driver_id);
	$mail = get_field('driver_mail', $driver_id);
	$telpriv = get_field('driver_phone_privat', $driver_id);
	$telmob = get_field('driver_phone_mobile', $driver_id);
	$lfanr = get_field('driver_lfa_nr', $driver_id);
	$drivercat = get_field('driver_licensecategory', $driver_id);
	$teacher = get_field('driver_teacher', $driver_id);
	$field_values = array(
		'firstname' => $firstname,
		'lastname' => $lastname,
		'gender' => $gender,
		'job' => $job,
		'streetnr' => $streetnr,
		'plz' => $plz,
		'ort' => $ort,
		'country' => $country,
		'mail' => $mail,
		'telpriv' => $telpriv,
		'telmob' => $telmob,
		'lfanr' => $lfanr,
		'drivercat' => $drivercat,
		'teacher' => $teacher
	);
	gravity_form($form_id, false, false, false, $field_values, true);
	exit();
}
add_action( 'wp_ajax_fahrapp_show_user_edit_form', 'fahrapp_show_user_edit_form' );
add_action( 'wp_ajax_nopriv_fahrapp_show_user_edit_form', 'fahrapp_show_user_edit_form' );