function ilSubItemSelectionTableGUI($a_parent_obj, $a_parent_cmd, $a_ref_id, $a_cmd = "createExportFile", $a_cmd_txt = "")
 {
     global $ilCtrl, $lng;
     parent::__construct($a_parent_obj, $a_parent_cmd);
     $lng->loadLanguageModule("export");
     if ($a_cmd_txt == "") {
         $a_cmd_txt = $lng->txt("export_create_export_file");
     }
     $this->addColumn($lng->txt("export_resource"));
     $this->addColumn($lng->txt("export_last_export"));
     $this->addColumn($lng->txt("export_last_export_file"), "", "20%");
     $this->addColumn($lng->txt("export_create_new_file"), "", "20%");
     $this->addColumn($lng->txt("export_omit_resource"), "", "20%");
     $this->setFormAction($ilCtrl->getFormAction($a_parent_obj));
     $this->addCommandButton($a_cmd, $a_cmd_txt);
     $this->setRowTemplate("tpl.sub_item_selection_row.html", "Services/Export");
     $this->setTitle($lng->txt("export_select_resources"));
     include_once "./Services/Export/classes/class.ilExport.php";
     $this->setData(ilExport::_getValidExportSubItems($a_ref_id));
     $this->setLimit(99999);
 }