unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls;

type
  TForm1 = class(TForm)
    Timer1: TTimer;
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    { Private declarations }
    procedure DoOnIdle(Sender: TObject; var Done:
Boolean);
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.DoOnIdle(Sender: TObject; var
Done: Boolean);
begin
  Timer1.Enabled := False;
  Timer1.Enabled := True;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Application.OnIdle := DoOnIdle;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  ShowMessage('Shutdown!');
end;

end.