procedure TfrmMain.ActShowModalWindowExecute(Sender: TObject);
var
  TmpFrm: TfrmModal;
begin
  if Assigned(TfrmTemplate(Sender).Parent)
  then
    begin
      TmpFrm:= TfrmModal.Create(TfrmTemplate(Sender).Owner);//TTabSheet
      try
        TmpFrm.ShowModal;
      finally
        FreeAndNil(TmpFrm);
      end;
    end
  else
    begin
      TmpFrm:= TfrmModal.Create(TfrmTemplate(Sender));//undocked TfrmTemplate
      try
        EnableWindow(TfrmTemplate(Sender).Handle,False);//uses LCLIntf;
        TmpFrm.Show;
        while (TmpFrm.FormLiveState = flsOpen) and not Application.Terminated do
        begin
          Application.ProcessMessages;
          Application.Idle(False);
        end;
      finally
        EnableWindow(TfrmTemplate(Sender).Handle,True);
        FreeAndNil(TmpFrm);
      end;
    end;
end;