How I can retrieve the value sent (Method post or get) in the web service (nameOfPage.asmx) ?

private void button3_Click(object sender, EventArgs e)
        {
            // Postvars
            byte[] buffer = Encoding.ASCII.GetBytes("test=postvar&test2=another");
            //byte[] buffer = Encoding.ASCII.GetByteCount(label1.Text);
            //Initialization, we use localhost
            HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create("http://127.0.0.1/MyWebS.asmx");
            //Our method is post, otherwise the buffer (postvars) would be useless
            WebReq.Method = "POST";
            //We use form contentType, for the postvars.
            WebReq.ContentType = "application/x-www-form-urlencoded";
            //The length of the buffer (postvars) is used as contentlength.
            WebReq.ContentLength = buffer.Length;
            //We open a stream for writing the postvars
            Stream PostData = WebReq.GetRequestStream();
            //Now we write 
            PostData.Write(buffer, 0, buffer.Length);
            // Afterwards, we close. Closing is always important!
            PostData.Close();
            
            //Get the response handle
            //HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse();
            
            //Let's show some information about the response
            //Console.WriteLine(WebResp.StatusCode);
            //Console.WriteLine(WebResp.Server);

            //Now, we read the response (the string), and output it.
            //Stream Answer = WebResp.GetResponseStream();
            //StreamReader _Answer = new StreamReader(Answer);
            //Console.WriteLine(_Answer.ReadToEnd());
  
        }