public function pager() {
        global $OUTPUT;

        return $OUTPUT->paging_bar(
            $this->totalitemcount, $this->page, $this->perpage,
            new moodle_url('/grade/report/singleview/index.php', array(
                'perpage' => $this->perpage,
                'id' => $this->courseid,
                'group' => $this->groupid,
                'itemid' => $this->itemid,
                'item' => 'grade'
            ))
        );
    }