Ник В

private const string _site = "https://www.fdworlds.net/";
        private const string _login = "";
        private const string _passw = "";
        private CookieContainer _cookie = new CookieContainer();

        private string POST(string _site, string _data, string _referer)
        {
            HttpWebRequest postRequest = (HttpWebRequest) WebRequest.Create(_site);
            {
                postRequest.Method = "POST";
                postRequest.Timeout = 100000;
                postRequest.Host = "www.fdworlds.net";
                postRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0";
                postRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
                postRequest.Referer = _referer;
                postRequest.CookieContainer = _cookie;
                postRequest.ContentType = "application/x-www-form-urlencoded";
                byte[] sentData = Encoding.GetEncoding(1251).GetBytes(_data);
                postRequest.ContentLength = sentData.Length;
                Stream sendStream = postRequest.GetRequestStream();
                sendStream.Write(sentData, 0, sentData.Length);
                sendStream.Close();
            }
            WebResponse resp = postRequest.GetResponse();
            Stream ReceiveStream = resp.GetResponseStream();
            StreamReader sr = new StreamReader(ReceiveStream, Encoding.GetEncoding(1251));
            Char[] read = new Char[256];
            int count = sr.Read(read, 0, 256);
            string Out = String.Empty;
            while (count > 0)
            {
                String str = new String(read, 0, count);
                Out += str;
                count = sr.Read(read, 0, 256);
            }
            return Out;
        }

        private string GET(string _site, string _data, string _referer)
        {
            HttpWebRequest getRequest = (HttpWebRequest) WebRequest.Create(_site + "?" + _data);
            {
                getRequest.Method = "GET";
                getRequest.Host = "www.fdworlds.net";
                getRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:28.0) Gecko/20100101 Firefox/28.0";
                getRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
               if (_referer != null)
                   getRequest.Referer = _referer;
                getRequest.CookieContainer = _cookie;
            }
            WebResponse resp = getRequest.GetResponse();
            Stream ReceiveStream = resp.GetResponseStream();
            StreamReader sr = new StreamReader(ReceiveStream, Encoding.GetEncoding(1251));
            Char[] read = new Char[256];
            int count = sr.Read(read, 0, 256);
            string Out = String.Empty;
            while (count > 0)
            {
                String str = new String(read, 0, count);
                Out += str;
                count = sr.Read(read, 0, 256);
            }
            return Out;
        }

        public Form1()
        {
            InitializeComponent();
        }

        private void btnConnect_Click(object sender, EventArgs e)
        {
            txb_text.Text = POST(_site + "enter.php", "login=" + _login + "&pass=" + _passw, "https://www.fdworlds.net/auth.php");
            txb_text.Text = GET(_site + "inv_user.php", " ", "http://www.fdworlds.net/inv_user.php");
        }
    }
}