MessageBox (or MessageDlg) Placement

procedure centered (Sender: TObject; Action: string);
begin
  form2.position := pomainformcenter;
  form3.position := pomainformcenter;
  form4.position := pomainformcenter;
  ConfirmDlg.position := pomainformcenter;
end;

procedure closeform(Sender: TObject; var CloseForm: Boolean);
//procedure Form1_Button1_OnClick (Sender: TObject; var Cancel: boolean);
begin
    if ConfirmDialog('Warning! Please confirm', 'Please Confirm') then
    begin
        showmessage('confirmed');
    end else CloseForm := False;
end;

procedure ConfirmDlg_btConfirm_OnClick (Sender: TObject; var Cancel: boolean);
begin
    ConfirmDlg.Tag := 1;
end;

function ConfirmDialog(msg, title: String): Boolean;
begin
    ConfirmDlg.Caption := title;
    ConfirmDlg.Tag := 0;
    ConfirmDlg.btConfirm.Cancel := False;
    ConfirmDlg.cMsg.Caption := msg;
    ConfirmDlg.ShowModal;
    result := ConfirmDlg.Tag <> 0;
end;


begin
  form1.menu := nil;
  form1.onclosequery := @closeform;
end.