How to get html of a page after authorization

подскажите как получить html страницы после авторизации

byte[] bytes = Encoding.GetEncoding(1251).GetBytes(string.Format("user={0}&pass={1}&login_submit=%CE%F2%EF%F0%E0%E2%E8%F2%FC", login, password));
httpRequest.ClearAllHeaders();
httpRequest.KeepAlive = true;
httpRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.162 Safari/535.19";
httpRequest.Referer = "https://site.ru";
httpRequest.ContentType = "application/x-www-form-urlencoded; charset=UTF-8";
httpRequest.AllowAutoRedirect = false;
httpRequest.Cookies = Network.Cookie;
if (httpRequest.Post("https:site.ru", bytes).HasRedirect)

Code

byte[] bytes = Encoding.GetEncoding(1251).GetBytes(string.Format("user={0}&pass={1}&login_submit=%CE%F2%EF%F0%E0%E2%E8%F2%FC", login, password));

                httpRequest.ClearAllHeaders();

                httpRequest.KeepAlive = true;

                httpRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.19 (KHTML, like Gecko) Chrome/18.0.1025.162 Safari/535.19";

                httpRequest.Referer = "https://site.ru";

                httpRequest.ContentType = "application/x-www-form-urlencoded; charset=UTF-8";

                httpRequest.AllowAutoRedirect = false;

                httpRequest.Cookies = Network.Cookie;

                if (httpRequest.Post("https:site.ru", bytes).HasRedirect)