tableCtr.addColumnDescriptor(coldesc);
    } else {
      tableCtr.addColumnDescriptor(new DefaultColumnDescriptor("table.header.filename", 0, null, loc));
    }
    if (callback != null) {
      StaticColumnDescriptor statColdesc = new StaticColumnDescriptor(DialogElementsController.ACTION_START_FORUM, "table.header.forum",
          translator.translate("dialog.start"));
      // if configured open forum as popup
      String integration = (String) config.get(DialogConfigForm.DIALOG_CONFIG_INTEGRATION);
      if (integration.equals(DialogConfigForm.CONFIG_INTEGRATION_VALUE_POPUP)) {
        statColdesc.setIsPopUpWindowAction(true, DefaultColumnDescriptor.DEFAULT_POPUP_ATTRIBUTES);
      }
      tableCtr.addColumnDescriptor(statColdesc);
    }
    tableCtr.addColumnDescriptor(new DefaultColumnDescriptor("table.header.author", 1, null, loc));
    tableCtr.addColumnDescriptor(false, new DefaultColumnDescriptor("table.header.size", 2, null, loc));
    tableCtr.addColumnDescriptor(new DefaultColumnDescriptor("table.header.date", 3, null, loc));
    if (callback != null) tableCtr.addColumnDescriptor(new DefaultColumnDescriptor("table.header.newmessages", 4, null, loc));
    if (callback != null) tableCtr.addColumnDescriptor(new DefaultColumnDescriptor("table.header.messages", 5, null, loc));
    // callback is null in course editor environement where we dont need
    // security calls
    if (callback != null && callback.mayDeleteMessageAsModerator()) tableCtr.addColumnDescriptor(new StaticColumnDescriptor(
        DialogElementsController.ACTION_DELETE_ELEMENT, "table.header.action", translator.translate("delete")));
  }