drupal_set_message() in user_logout

http://drupal.org/node/754560


   $cookieParams = session_get_cookie_params();
    session_start();
    session_set_cookie_params($

cookieParams);
  // Load the anonymous user
  $user = drupal_anonymous_user(session_id());
  drupal_set_message(t('You have successfully logged out of the system. Enter your Username and Passwords below to login again.'));