class Net
      {
            
          string remixsid;  //Id сессии
          public string lastCookies; //Куки

          public string GetHtml(string url, string postData) //Возвращает содержимое поданной страницы
          {
              string HTML = "";

              Regex rex1 = new Regex("remixsid=(.*?);", RegexOptions.Multiline | RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace);
              if (url == "0") return "0"; //Проверка на ошибку
              HttpWebRequest myHttpWebRequest =(HttpWebRequest)HttpWebRequest.Create(url);
              //myHttpWebRequest.Proxy = new WebProxy("127.0.0.1", 8888); //В перспективе можно использовать прокси
              if (!String.IsNullOrEmpty(postData)) myHttpWebRequest.Method = "POST";
              myHttpWebRequest.Referer = "https://vk.com";
              myHttpWebRequest.UserAgent = "Mozila/14.0 (compatible; MSIE 6.0;Windows NT 5.1; SV1; MyIE2;";
              myHttpWebRequest.Accept = "image/gif, image/x-xbitmap, image/jpeg,image/pjpeg, application/x-shockwave-flash,application/vnd.ms-excel,application/vnd.ms-powerpoint,application/msword";
              myHttpWebRequest.Headers.Add("Accept-Language", "ru");
              myHttpWebRequest.ContentType = "application/x-www-form-urlencoded";
              myHttpWebRequest.KeepAlive = false;

              // передаем Сookie, полученные в предыдущем запросе
              if (!String.IsNullOrEmpty(this.remixsid))
              {
                  lastCookies = "remixchk=5;remixsid=" + this.remixsid;
              }
              if (!String.IsNullOrEmpty(lastCookies))
              {
                  myHttpWebRequest.Headers.Add(System.Net.HttpRequestHeader.Cookie, lastCookies);
              }
              // ставим False, чтобы при получении кода 302, не делать   
              // автоматического перенаправления
              myHttpWebRequest.AllowAutoRedirect = false;
             
              // передаем параметры
              string sQueryString = postData;
              byte[] ByteArr = System.Text.Encoding.GetEncoding(1251).GetBytes(sQueryString); //Вконтакте использует кирилическую кодировку
              try
              {
                  if (!String.IsNullOrEmpty(postData))
                  {
                      myHttpWebRequest.ContentLength = ByteArr.Length;
                      myHttpWebRequest.GetRequestStream().Write(ByteArr, 0, ByteArr.Length);
                  };

                  // делаем запрос
                  HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
                  StreamReader myStreamReader;
                    
                  //Сохраняем Cookie   
                  lastCookies = String.IsNullOrEmpty(myHttpWebResponse.Headers["Set-Cookie"]) ? "" : myHttpWebResponse.Headers["Set-Cookie"];
                  Match matc1 = rex1.Match(lastCookies);
                    
                  //Если есть имя сессии, то подменяем Cookie   
                  if (matc1.Groups.Count == 2) { this.remixsid = matc1.Groups[1].ToString(); lastCookies = "remixchk=5;remixsid=" + this.remixsid; }
                  if (myHttpWebResponse.Headers["Content-Type"].IndexOf("windows-1251") > 0)
                  {
                      myStreamReader = new StreamReader(myHttpWebResponse.GetResponseStream(), Encoding.GetEncoding("windows-1251"));
                  }
                  else
                  {
                      myStreamReader = new StreamReader(myHttpWebResponse.GetResponseStream(), Encoding.UTF8);
                  }
                  HTML = myStreamReader.ReadToEnd();
                  if (HTML == "") //Проверяем на редирект
                  {
                      HTML = this.GetHtml(myHttpWebResponse.Headers["Location"].ToString(), "");

                  }
              }
              catch (Exception err)
              {
                  //Ошибка в чтении страницы
                  return "0";
              }
              return HTML;
          }
      }