Как показать оставшееся время до конца?

Code:

Procedure TForm1.Timer1Timer(Sender: TObject);

Var

TheLength,Posi,SummaMin,SummaSec: Integer;

begin

//Progress Bar to check if the track is playing

if Progress.Max<>0 then Begin

   Progress.Position := Mediaplayer1.Position;

    //Gets the length of the selected track

   TheLength := Mediaplayer1.TrackLength[ListBox1.ItemIndex];

     //gets the current position of the track

     Posi := Mediaplayer1.Position;

     //Caculates Minutes

     SummaMin := ((TheLength - Posi) div 1000) Div 60;

     //Calculates Seconds

     SummaSec := ((TheLength - Posi) Div 1000) Mod 60;

     //Adds zero if Seconds are less then ten

     If SummaSec < 10 Then

     Label2.Caption := '0' + IntToStr(SummaSec)

     Else

     Label2.Caption := IntToStr(SummaSec);

     //Minutes

     Label1.Caption := IntToStr(SummaMin);

End;