post data from using code behind

//Create a request using a URL that can receive a post. 
WebRequest request = WebRequest.Create("http://forum.example.ir");

 //Set the Method property of the request to POST.
 request.Method = "POST";

//Create POST data and convert it to a byte array.
 string postData = "username=user&passsword=pass&email=behnamhagi@gmail.com";
 byte[] byteArray = Encoding.UTF8.GetBytes(postData);

//Set the ContentType property of the WebRequest.
 request.ContentType = "application/x-www-form-urlencoded";
 
//Set the ContentLength property of the WebRequest.
 request.ContentLength = byteArray.Length;
 
//Get the request stream.
 Stream dataStream = request.GetRequestStream();

//Write the data to the request stream.
 dataStream.Write(byteArray, 0, byteArray.Length);

//Close the Stream object.
 dataStream.Close();

//Get the response.
 WebResponse response = request.GetResponse();

//Display the status.
 Console.WriteLine(((HttpWebResponse)response).StatusDescription);

//Get the stream containing content returned by the server.
 dataStream = response.GetResponseStream();

//Open the stream using a StreamReader for easy access.
 StreamReader reader = new StreamReader(dataStream);

//Read the content.
 string responseFromServer = reader.ReadToEnd();

//Display the content.
 Console.WriteLine(responseFromServer);

//Clean up the streams.
 reader.Close();
 dataStream.Close();
 response.Close();