public function perpage_selector($current=10) {

        $options = array();
        foreach (array(10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 1000) as $option) {
            if ($option != $current) {
                $options[$option] = $option;
            }
        }
        $select = new single_select($this->page->url, 'perpage', $options, '', array('' => get_string('showingperpagechange', 'mod_workshop')));
        $select->label = get_string('showingperpage', 'mod_workshop', $current);
        $select->method = 'post';

        return $this->output->container($this->output->render($select), 'perpagewidget');
    }