Help:ActiveX program in Delphi

[p2o5]

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

type
TForm1 = class(TForm)
VLCPlugin21: TVLCPlugin2;
private
id1,id2,id3 :Integer;
.......

procedure TForm1.Button1Click(Sender: TObject);
Var
op : Array of String;
begin
setlength(op,2);
op[0]:=':aspect-ratio=4:3';
op[1]:='--rtsp-tcp';
id1:=VLCPlugin21.playlist.add('file://H:/share/film/Jumper.2008.TS.XVID-PREVAiL.avi','x1',':aspect-ratio=4:3');
id2:=VLCPlugin21.playlist.add('file://H:/share/film/JS-CD1.rmvb','x2',op);
id3:=VLCPlugin21.playlist.add('http://192.168.1.1:81','x3',op);
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
VLCPlugin21.playlist.playItem(id1); //Why not working!!!!!!!!!!!!!! playItem(id2),playItem(id3) are same.....
end;
.......