HttpWebRequest postReq = (HttpWebRequest) WebRequest.Create("https://sp-money.yandex.ru");
            postReq.Method = "POST";
            postReq.Timeout = 120000; // Устанавливаем таймаут соединения
            postReq.ContentType = "application/x-www-form-urlencoded; charset=UTF-8";
            ServicePointManager.Expect100Continue = false;
            // Формируем параметры запроса
            string data = string.Format("client_id={0}&scope=account history operation&redirect_uri={1}",
                                        SettingsStore.YmAppId,
                                        HttpUtility.UrlEncode(SettingsStore.YmRedirectUri, Encoding.UTF8));

            byte[] sentData = Encoding.UTF8.GetBytes(data);
            StreamWriter sendStream = null;
            postReq.ContentLength = sentData.Length;
            try
            {
                sendStream = new StreamWriter(postReq.GetRequestStream());
                sendStream.Write(data);
            }
            finally 
            {
                if (sendStream != null)
                    sendStream.Close();
            }

            Response.Redirect("https://sp-money.yandex.ru");