public function addTimestampValidationPageAlert($errorMessage, $existingObject, $action)
    {
        $authorId = $existingObject->get('modification_author_id');
        if (!$authorId) {
            $authorId = $existingObject->get('author_id');
        }
        $author = AuthorManager::fetchByID($authorId);
        $formatteAuthorName = $authorId === Symphony::Author()->get('id')
            ? __('yourself')
            : (!$author
                ? __('an unknown user')
                : $author->get('first_name') . ' ' . $author->get('last_name'));

        $msg = $this->_errors['timestamp'] . ' ' . __(
            'made by %s at %s.', array(
                $formatteAuthorName,
                Widget::Time($existingObject->get('modification_date'))->generate(),
            )
        );

        $currentUrl = Administration::instance()->getCurrentPageURL();
        $overwritelink = Widget::Anchor(
            __('Replace changes?'),
            $currentUrl,
            __('Overwrite'),
            'js-tv-overwrite',
            null,
            array(
                'data-action' => General::sanitize($action)
            )
        );
        $ignorelink = Widget::Anchor(
            __('View changes.'),
            $currentUrl,
            __('View the updated entry')
        );
        $actions = $overwritelink->generate() . ' ' . $ignorelink->generate();
        
        $this->pageAlert("$msg $actions", Alert::ERROR);
    }