V Delphi by to vyzeralo nejak takto:

unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs;

type
  TForm1 = class(TForm)
    procedure WndProc(var Msg : TMessage); override;
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{ TForm1 }

procedure TForm1.WndProc(var Msg: TMessage);
begin
  if Msg.Msg = WM_SYSCOMMAND then
    if Msg.WParam =sc_Minimize then
    begin
      if Application.MessageBox(
			'Naozaj chceš minimalizovať okno?',
			'Potvrdenie',
			MB_YESNO Or MB_ICONQUESTION) = IDNO then Exit
    end;
  inherited;
end;

end.