public function course_search_form($value = '', $format = 'plain') {
        static $count = 0;
        $formid = 'coursesearch';
        if ((++$count) > 1) {
            $formid .= $count;
        }

        switch ($format) {
            case 'navbar' :
                $formid = 'coursesearchnavbar';
                $inputid = 'navsearchbox';
                $inputsize = 20;
                break;
            case 'short' :
                $inputid = 'shortsearchbox';
                $inputsize = 12;
                break;
            default :
                $inputid = 'coursesearchbox';
                $inputsize = 30;
        }

        $strsearchcourses = get_string("searchcourses");
        $searchurl = new moodle_url('/course/management.php');

        $output = html_writer::start_div('row');
        $output .= html_writer::start_div('col-md-12');
        $output .= html_writer::start_tag('form', array('class' => 'card', 'id' => $formid,
                'action' => $searchurl, 'method' => 'get'));
        $output .= html_writer::start_tag('fieldset', array('class' => 'coursesearchbox invisiblefieldset'));
        $output .= html_writer::tag('div', $this->output->heading($strsearchcourses.': ', 2, 'm-0'),
                array('class' => 'card-header'));
        $output .= html_writer::start_div('card-body');
        $output .= html_writer::start_div('input-group col-sm-6 col-lg-4 m-auto');
        $output .= html_writer::empty_tag('input', array('class' => 'form-control', 'type' => 'text', 'id' => $inputid,
                'size' => $inputsize, 'name' => 'search', 'value' => s($value)));
        $output .= html_writer::start_tag('span', array('class' => 'input-group-btn'));
        $output .= html_writer::tag('button', get_string('go'), array('class' => 'btn btn-primary', 'type' => 'submit'));
        $output .= html_writer::end_tag('span');
        $output .= html_writer::end_div();
        $output .= html_writer::end_div();
        $output .= html_writer::end_tag('fieldset');
        $output .= html_writer::end_tag('form');
        $output .= html_writer::end_div();
        $output .= html_writer::end_div();

        return $output;
    }