private function action_delete()
    {
        $mbox = trim(rcube_utils::get_input_value('_mbox', rcube_utils::INPUT_POST, true)); //UTF7-IMAP
        $user = trim(rcube_utils::get_input_value('_user', rcube_utils::INPUT_POST));

        $user = explode(',', $user);

        foreach ($user as $u) {
            $u = trim($u);
            if ($this->rc->storage->delete_acl($mbox, $u)) {
                $this->rc->output->command('acl_remove_row', rcube_utils::html_identifier($u));
            }
            else {
                $error = true;
            }
        }

        if (!$error) {
            $this->rc->output->show_message('acl.deletesuccess', 'confirmation');
        }
        else {
            $this->rc->output->show_message('acl.deleteerror', 'error');
        }
    }