AdvMessage login validation

I am trying to redisplay AdvMessage but "Show" does not work. What am I doing wrong?

procedure TframMenu.AdvMsgLoginButtonClick(Sender: TObject;
      EventParams: TStringList; ButtonIndex: Integer; InputString,
      InputPassword: string; InputCheck: Boolean; var Allow: Boolean); begin

   with AdvMessageDial do begin
      Notes := 'Invalid password'; Show; exit; end;

Thanks
Tom Obenschain

I got it. Instead of Show, I needed to set Allow to false.