function display_virtual_course_list()
{
    $course_list = CourseManager::get_virtual_course_list();
    if (!is_array($course_list)) {
        //there are no virtual courses
        echo "<i>" . get_lang('ThereAreNoVirtualCourses') . "</i>";
        return;
    }
    $column_header[] = array(get_lang('Title'), true);
    $column_header[] = array(get_lang('Code'), true);
    $column_header[] = array(get_lang('VisualCode'), true);
    $column_header[] = array(get_lang('LinkedCourseTitle'), true);
    $column_header[] = array(get_lang('LinkedCourseCode'), true);
    $table_data = array();
    for ($i = 0; $i < count($course_list); $i++) {
        $course_list[$i] = Database::generate_abstract_course_field_names($course_list[$i]);
        $target_course_code = $course_list[$i]["target_course_code"];
        $real_course_info = Database::get_course_info($target_course_code);
        $row = array();
        $row[] = $course_list[$i]["title"];
        $row[] = $course_list[$i]["system_code"];
        $row[] = $course_list[$i]["visual_code"];
        $row[] = $real_course_info["title"];
        $row[] = $real_course_info["system_code"];
        $table_data[] = $row;
    }
    Display::display_sortable_table($column_header, $table_data, array(), array(), array('action' => $_GET['action']));
}