Hello , i get this error message : The underlying connection was closed: The connection was closed unexpectedly at this code


Code:
 try
                {

                    HttpWebRequest req = (HttpWebRequest)WebRequest.Create("http://x.x.x.x:4042/admin.cgi?pass=test&mode=viewxml");

                    req.ContentType = "text/xml;charset=\"utf-8\"";
                    req.Accept = "text/xml";
                    req.Method = "HEAD";

                    WebResponse resp = req.GetResponse();
                    
                    StreamReader r = new StreamReader(resp.GetResponseStream());

                    richTextBox1.AppendText(r.ReadToEnd()+"\n");


                }
                catch (System.Net.WebException webe)
                {
                    richTextBox1.AppendText(webe.ToString() + "\n");
                    richTextBox1.AppendText(webe.Response.ToString() + "\n");
                    richTextBox1.AppendText(webe.Message.ToString());

                }



can you help me ? thanks