csharp post form data

     
       public string POST(string url, string username,string password, string postParams)
       {


           //Our getVars, to test the get of our php. 
           //We can get a page without any of these vars too though.
           //string getVars = "?var1=test1&var2=test2";
           //Initialization, we use localhost, change if applicable
           HttpWebRequest WebReq = (HttpWebRequest)WebRequest.Create(url);
           WebReq.UserAgent = GetRndUserAgent();

           string Credentials = Convert.ToBase64String(Encoding.ASCII.GetBytes(username + ":" + password));

           WebReq.Method = "POST";
           WebReq.ContentType = "application/xml";
           WebReq.AllowWriteStreamBuffering = true;

           WebReq.Headers.Add("Authorization", "Basic " + Credentials);

           WebReq.ServicePoint.Expect100Continue = false;



          // string postParams = "name=some sort of value";
           if (postParams != string.Empty)
           {
               byte[] buffer = ASCIIEncoding.UTF8.GetBytes(postParams);
               WebReq.ContentLength = buffer.Length;
               using (Stream writer = WebReq.GetRequestStream())
               {

                   writer.Write(buffer, 0, buffer.Length);

               }
           }

           //From here on, it's all the same as above.
           HttpWebResponse WebResp = (HttpWebResponse)WebReq.GetResponse();
           //Let's show some information about the response
           //_log(WebResp.StatusCode.ToString());
           //_log(WebResp.Server);

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


       }