class Program
    {
        private static bool SendPost(string url, string postData)
        {
            var httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
            httpWebRequest.AllowAutoRedirect = false;
            httpWebRequest.Method = "POST";
            httpWebRequest.UserAgent = "User-Agent=Mozilla/5.0 (Windows; U; Windows NT 5.1; ru; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7 (.NET CLR 3.5.30729)";
            httpWebRequest.ContentType = "application/x-www-form-urlencoded";
            httpWebRequest.ProtocolVersion = HttpVersion.Version10;
            httpWebRequest.Referer = "http://www.voyna-plemyon.ru/";
            var buffer = Encoding.ASCII.GetBytes(postData);
            httpWebRequest.ContentLength = buffer.Length;
            using (var writer = httpWebRequest.GetRequestStream())
            {
                writer.Write(buffer, 0, buffer.Length);
            }
            using (var httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse())
            {
                var location = httpWebResponse.Headers.Get("Location") ?? "";
                return location.IndexOf("server_id=ru1", StringComparison.InvariantCulture) != -1;
            }
        }

        static void Main(string[] args)
        {
            var user = "";
            var pwd = "";

            var b = SendPost("http://www.voyna-plemyon.ru/index.php?action=login", string.Format("user={0}&clear=true&password={1}&server=ru1", user, pwd));
            Console.WriteLine(b);
        }
    }