Ограничение по времени Делфи

Программа тестирование. Нужно поставить ограничение по времени на каждый тест.
unit Unit1;

interface

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

type
TForm1 = class(TForm)
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
Label4: TLabel;
RadioButton1: TRadioButton;
RadioButton2: TRadioButton;
RadioButton3: TRadioButton;
Button1: TButton;
Label5: TLabel;
procedure FormCreate(Sender: TObject);
procedure RadioButton1Click(Sender: TObject);
procedure RadioButton2Click(Sender: TObject);
procedure RadioButton3Click(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1; f:TextFile; nq:integer; right:integer;
level:array[1..4] of integer;
mes:array[1..4] of string;
buf:string;

implementation

{$R *.dfm}
Function NextQw:boolean;
label x;
begin
if not EOF(f) then
begin
readln(f,Buf);
Form1.Label1.Caption:=Buf;

readln(f,Buf);
Form1.Label2.Caption:=Buf;
readln(f,Buf);
form1.RadioButton1.Tag:=strtoint(buf);

readln(f,Buf);
Form1.Label3.Caption:=Buf;
readln(f,Buf);
form1.RadioButton2.Tag:=strtoint(buf);

readln(f,Buf);
Form1.Label4.Caption:=Buf;
readln(f,Buf);
form1.RadioButton3.Tag:=strtoint(buf);

nq:=nq+1;
form1.Button1.Enabled:=False;
Form1.RadioButton1.Checked:=False;
Form1.RadioButton2.Checked:=False;
Form1.RadioButton3.Checked:=False;
NextQw:=True;
end
else nextQw:=False;
end;
procedure TForm1.FormCreate(Sender: TObject);
var i:integer;
fname:string;
begin
fname:='test.txt';
assignFile(f,fname);
try reset(f)
except
on EInOutError do
Begin
ShowMessage('Ïîìèëêà çâåðíåííÿ äî ôàéëó òåñòà:'+fname);
Application.Terminate;
end;
end;

readln(f,Buf);
Form1.Caption:=Buf;
for i:=1 to 4 do
begin
Readln(F,Buf);
mes:=Buf;
Readln(f,Buf);
level:=StrToInt(buf);
end;
right:=0;
nq:=0;
NextQw;

end;

procedure TForm1.RadioButton1Click(Sender: TObject);
begin
Button1.Enabled:=True;
end;

procedure TForm1.RadioButton2Click(Sender: TObject);
begin
Button1.Enabled:=True;
end;

procedure TForm1.RadioButton3Click(Sender: TObject);
begin
Button1.Enabled:=True;
end;

procedure TForm1.Button1Click(Sender: TObject);
var buf: string;
i:integer;
begin
if Button1.Caption='Çàâåðøèòè'Then Close;
if radioButton1.Checked then right:=right+radioButton1.Tag;
if radioButton2.Checked then right:=right+radioButton2.Tag;
if radioButton3.Checked then right:=right+radioButton3.Tag;
if not NextQW then
begin
Button1.Caption:='Çàâåðøèòè';
radioButton1.Visible:=False;
Label2.Visible:=False;
radioButton2.Visible:=False;
Label3.Visible:=False;
radioButton3.Visible:=False;
Label4.Visible:=False;
Buf:='Òåñòóâàííÿ çàê³í÷åíî.'+#13+'Ïðàâèëüíèõ â³äïîâ³äåé:'+inttostr(right)+
' Çàïèòàíü'+inttostr(nq)+'.'+#13;
I:=1;
While(right) and (i<4) do
inc(i);
buf:=Buf+mes;

Label1.AutoSize:=True;
Label1.Caption:=Buf;
end;

end;

end.