Advanced Drupal $form_state['redirect']

drupal_form_state_redirect.php

function mymodule_wizard_submit($form, &$form_state) {
  $wizard = $form_state['values']['wizard'];
  // $form_state['redirect'] = lazy drupal_goto, has the same parameters
  $path = trim(parse_url($form['#action'], PHP_URL_PATH), '/');
  $query = array('sender' => $wizard['sender'], 'recipient' => $wizard['recipient']);
  $form_state['redirect'] = array($path, $query);
}