unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Timer1: TTimer;
    Edit1: TEdit;
    Button1: TButton;
    Button2: TButton;
    Timer2: TTimer;
    procedure Timer1Timer(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Timer2Timer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  x:DOUBLE;

implementation

{$R *.dfm}

procedure TForm1.Timer1Timer(Sender: TObject);


begin
x:=strToFloat(Edit1.Text);
begin
if x> 0 then
x:=x-1;
Edit1.Text := CurrToStr(x);
end;
end;


procedure TForm1.Button1Click(Sender: TObject);
begin
Timer1.Enabled:=True;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
Timer1.Enabled:=false;
end;

procedure TForm1.Timer2Timer(Sender: TObject);
begin
if (Edit1.text<='0') and (Edit1.text<>'') then
begin

Timer1.Enabled:=False;
Edit1.Text:='時間到';   MessageBeep(0);
end;
end;
end.