string POST(string URL, string data)
        {
            WebRequest req = WebRequest.Create(URL);
            req.Method = "POST";
            req.Timeout = 60000;
            req.ContentType = "application/x-www-form-urlencoded";

            byte[] sentData = Encoding.GetEncoding(1251).GetBytes(data);
            req.ContentLength = sentData.Length;

            Stream sendStream = req.GetRequestStream();
            sendStream.Write(sentData, 0, sentData.Length);
            sendStream.Close();

            WebResponse res = req.GetResponse();
            Stream ReceiveStream = res.GetResponseStream();
            StreamReader sr = new StreamReader(ReceiveStream, Encoding.UTF8);
            //Кодировка указывается в зависимости от кодировки ответа сервера
            Char[] read = new Char[256];
            int count = sr.Read(read, 0, 256);

            string output = String.Empty;
            while (count > 0)
            {
                String str = new String(read, 0, count);
                output += str;
                count = sr.Read(read, 0, 256);
            }

            return output;
        }