public static function manage_site_registration()
 {
     global $nelioab_admin_controller;
     if (isset($_POST['nelioab_registration_action'])) {
         $action = $_POST['nelioab_registration_action'];
         try {
             switch ($action) {
                 case 'register':
                     $type = 'unknown';
                     if (isset($_POST['nelioab_registration_type'])) {
                         $type = $_POST['nelioab_registration_type'];
                     }
                     $sector = 'unknown';
                     if (isset($_POST['nelioab_registration_sector'])) {
                         $sector = $_POST['nelioab_registration_sector'];
                     }
                     NelioABAccountSettings::register_this_site($type, $sector);
                     $nelioab_admin_controller->message = __('This site has been successfully activated in your account.', 'nelioab');
                     break;
                 case 'deregister':
                     NelioABAccountSettings::deregister_this_site();
                     $nelioab_admin_controller->message = __('This site is no longer active in your account.', 'nelioab');
                 case 'unlink':
                     NelioABAccountSettings::unlink_this_site();
                     $nelioab_admin_controller->message = __('The site is no longer linked to any of your other active sites. If you have free slots, you may now activate it as a completely different and new site.', 'nelioab');
             }
         } catch (Exception $e) {
             require_once NELIOAB_ADMIN_DIR . '/error-controller.php';
             NelioABErrorController::build($e);
         }
     }
 }