unit Unit1; 

interface 

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

type 
        TForm1 = class(TForm) 
        tmr1: TTimer; 
        lbl1: TLabel; 
        Button1: TButton; 
        procedure tmr1Timer(Sender: TObject); 
        procedure Button1Click(Sender: TObject); 
    private 
        { Private declarations } 
    public 
        { Public declarations } 
    end; 

var 
    Form1: TForm1; 

implementation 
var 
    i:Integer; 


{$R *.dfm} 

procedure TForm1.tmr1Timer(Sender: TObject); 

begin 
             Lbl1.Caption:=IntToStr(i); 
             Dec(i); 
             if i < 0 then tmr1.Enabled:=False; 
end; 

procedure TForm1.Button1Click(Sender: TObject); 
begin 
            i:=10000; 
            tmr1.Enabled:=True; 
end; 

end.