function action_add()
 {
     $crsid = cm_get_param('crsid', 0);
     if ($classes = cmclass_get_listing('startdate', 'ASC', 0, 0, '', '', $crsid, true)) {
         $table = new addclasstable($classes);
         $table->print_table();
     } else {
         print_heading(get_string('no_classes_available', 'block_curr_admin'));
     }
 }