function subhub_magicapi_2_app_block_form_ajax_callback(&$form, &$form_state) {

  $commands['#type'] = 'ajax';
  $commands['#commands'][] = ajax_command_insert(NULL, drupal_render($form['settings']));
  $commands['#commands'][] = ajax_command_prepend(NULL, theme('status_messages'));

  // If the form was validated & submitted, dismiss the dialogue & replace the block.
  if($form_state['executed']) {

    // Un-dialogue the dialogue.
    $commands['#commands'][] = ajax_command_invoke('div.settings', 'dialog', array('destroy'));

    // Remove it from the DOM.
    $commands['#commands'][] = ajax_command_remove('div.settings');

    // Reload the block that we've altered
    $delta = $form_state['build_info']['args'][0];
    $rendered_block = subhub_magicapi_2_block_renderer($delta);

    $instance = subhub_magicapi_2_split_delta($delta);

    // Using the block id to replace here doesn't work for some reason...
    $commands['#commands'][] = ajax_command_replace('div.mbid-' . $instance['mbid'], $rendered_block);
  }

  return $commands;
}