unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  hThrad:THAndle;

implementation

{$R *.dfm}
Function Thead(P:Pointer):LongInt;
  var
    i:Integer;
  begin
    i:=0;
    while True do
      begin
        Form1.Memo1.Lines.Add(IntToStr(i));
        Inc(i);
        Sleep(1000)
      end;
  end;
procedure TForm1.Button1Click(Sender: TObject);
  var
    thr:Cardinal;
  begin
    hThrad:=createthread(nil,0,@Thead,nil,0,thr); 
  end;

procedure TForm1.Button2Click(Sender: TObject);
  begin
    TerminateThread(hThrad,0);
  end;

end.