ASP.NET

private string ProcessFormPOST(string strURL, string strFormData)
       {
           try
           {
               //string strViewstate = GetInitialViewState(strURL);
               //strViewstate = System.Web.HttpUtility.UrlEncode(strViewstate);
               //strFormData += "&__VIEWSTATE=" + strViewstate;

               byte[] buffer = Encoding.UTF8.GetBytes(strFormData);
               string proxy = null;

               System.Net.HttpWebRequest req = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(strURL);

               req.Method = "POST";
               req.ContentType = "application/x-www-form-urlencoded";
               req.ContentLength = buffer.Length;
               req.Proxy = new System.Net.WebProxy(proxy, true); // ignore for local addresses
               req.CookieContainer = new System.Net.CookieContainer(); // enable cookies

               System.IO.Stream reqst = req.GetRequestStream(); // add form data to request stream
               reqst.Write(buffer, 0, buffer.Length);
               //reqst.Flush();
               reqst.Close();

               System.Net.HttpWebResponse res = (System.Net.HttpWebResponse)req.GetResponse(); // send request, get response

               System.IO.Stream resst = res.GetResponseStream(); // display HTTP response
               System.IO.StreamReader sr = new System.IO.StreamReader(resst);

               return sr.ReadToEnd();
           }
           catch (Exception ex)
           {
               throw ex;
           }
       }