public function logout() {
		// clear session
		foreach ( $_SESSION as $key => $value ) {
			unset( $_SESSION[$key] );
		}

		// delete the session cookie on the client
		if ( ini_get( 'session.use_cookies' ) ) {
			$params = session_get_cookie_params();
			setcookie( session_name(), '', time() - 42000,
				$params['path'], $params['domain'],
				$params['secure'], $params['httponly']
			);
		}

		// destroy local session storage
		session_destroy();
		// generate new session id
		session_regenerate_id( true );
	}