private void add() {
    if (getWindow() != null) {
      return;
    }

    AdElementListModel model = new AdElementListModel();
    model.getIsEveryoneSelectionHidden().setEntity(true);
    setWindow(model);
    model.setTitle(ConstantsManager.getInstance().getConstants().addSystemPermissionToUserTitle());
    model.setHelpTag(HelpTag.add_system_permission_to_user);
    model.setHashName("add_system_permission_to_user"); // $NON-NLS-1$
    // model.Role.IsAvailable = true;
    // model.ExcludeItems = Items;

    UICommand tempVar = UICommand.createDefaultOkUiCommand("OnAttach", this); // $NON-NLS-1$
    model.getCommands().add(tempVar);
    UICommand tempVar2 = UICommand.createCancelUiCommand("Cancel", this); // $NON-NLS-1$
    model.getCommands().add(tempVar2);
  }