[NumLock]

captcha не нужна:

Код:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, IdBaseComponent, IdComponent, IdTCPConnection,
  IdTCPClient, IdHTTP;

type
  TForm1 = class(TForm)
    IdHTTP1: TIdHTTP;
    Memo1: TMemo;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  AStrings: TStrings;
  ACookie: String;
begin
  AStrings:=TStringList.Create;
  try
    IdHTTP1.HandleRedirects:=False;
    IdHTTP1.Request.UserAgent:='Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)';
    IdHTTP1.Request.ContentType:='application/x-www-form-urlencoded';
    IdHTTP1.Request.Host:='login.rutracker.org';
    IdHTTP1.Request.Referer:='http://rutracker.org/forum/index.php';
    IdHTTP1.Request.CustomHeaders.Add('Cookie: spylog_test=1');
    AStrings.Add('login_username=username');
    AStrings.Add('login_password=password');
    AStrings.Add('login=Вход');
    try
      Memo1.Text:=IdHTTP1.Post('http://login.rutracker.org/forum/login.php', AStrings);
      Memo1.Lines.SaveToFile('log.htm');
    except
      ACookie:=IdHTTP1.Response.RawHeaders.Values['Set-Cookie'];
      IdHTTP1.CookieManager.CookieCollection.Clear;
      IdHTTP1.Request.Clear;
      IdHTTP1.Request.CustomHeaders.Add('Cookie: '+ACookie);
      Memo1.Text:=IdHTTP1.Get(IdHTTP1.Response.Location);
      Memo1.Lines.SaveToFile('log.htm');
      if Pos('>Выход</a>', Memo1.Text)>0 then ShowMessage('Okay');
    end;
  finally
    AStrings.Free;
  end;
end;

end.