Keymaster_XH facilitates locking the administration area of a CMSimple_XH website, if a user is already logged in. This is necessary in case there is more than one user who has access to the back-end, as the back-end of CMSimple_XH does not take any precautions against concurrent editing. After a configurable period of inactivity the admin is automatically logged out, to avoid locking the site "forever", if they forgot to log out properly. Before this happens the admin is warned and offered the possibility to prolong the session, to avoid loosing unsaved changes.