Drupal 6 custom module to update all site caches

drupal_6_updateCache

function z_masterfit_ui_customized_menu() {
  $items = array();

  $items['admin/flush-cache'] = array(
  'type' => MENU_NORMAL_ITEM,
  'title' => t('Flush the cache'),
  'description' => 'Flush all website caches to make sure it updates to relect '.
    'your recent changes.',
  'page callback' => 'flush_cache_custom_callback',
  'access callback' => user_access('flush cache'),
  );

  return $items;
}

function z_masterfit_ui_customized_perm() {
  return array('flush cache');
}

function flush_cache_custom_callback() {
  drupal_flush_all_caches();

  drupal_set_message('Cache cleared.');

  drupal_goto('admin');
}