there is a way to remove the button, maybe it will help you:
Code:
procedure TForm1.sButton1Click(Sender: TObject);
var
msgDialog: TForm;
begin
msgDialog := CreateMessageDialog('Replace this with the message to be displayed', mtInformation, [mbYes,mbNo]);
try
msgDialog.Caption := 'Title of the dialog';
msgDialog.BorderIcons := []; // Message-Box have no title buttons
msgDialog.ShowModal;
finally
msgDialog.Hide;
msgDialog.Free;
end;
end;