function TForm.MyShowModal(const ModalCaler:TCustomForm=nil):integer;
var
 ActiveWindow: HWnd;
 p_WINDOW:Forms.TForm;

 //в TCustomForm для дельфей эта процедура protected, в Лазаре - private
  procedure CloseModal;
  var
    CloseAction: TCloseAction;
  begin
    try
      CloseAction := caNone;
      if CloseQuery then
      begin
        CloseAction := caHide;
        DoClose(CloseAction);
      end;
      case CloseAction of
        caNone: ModalResult := 0;
        caFree: Release;
      end;
      { do not call widgetset CloseModal here, but in ShowModal to
        guarantee execution of it }
    except
      ModalResult := 0;
      Application.HandleException(Self);
    end;
  end;

begin
  if Owner=nil
    then p_WINDOW:=Screen.ActiveForm
    else p_WINDOW:=Tform(owner);

  ActiveWindow := GetActiveWindow;

  if ModalCaler<>nil
    then modalform:=ModalCaler
    else modalform:=TForm(p_WINDOW);

  EnableWindow(p_WINDOW.Handle,False);
  ModalResult:=0;
  RecreateWnd(modalform);////в Лазаре процедура требует в качестве параметра константу TCustomForm 
  Include(FFormState, fsModal);
  Show;
  try
    SendMessage(Self.Handle, CM_ACTIVATE, 0, 0);
    repeat
      Application.HandleMessage;
      if (Application.Terminated) or (not visible)
        then ModalResult:= mrCancel
        else
          if ModalResult <> 0 then
          begin
            CloseModal;
            Break;
          end
    until ModalResult <> 0;

    Result:= ModalResult;
    SendMessage(Self.Handle, CM_DEACTIVATE, 0, 0);
    modalform:= nil;
  finally
    Hide;
  end;
  Exclude(FFormState, fsModal);
  EnableWindow(p_WINDOW.Handle,true);
  if GetActiveWindow = Self.Handle then SetActiveWindow(ActiveWindow);
end;

end.

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;