string url = "";

string usernamePassword = username + ":" + password;

HttpWebRequest myReq = (HttpWebRequest)WebRequest.Create(url);

myReq.Credentials = new NetworkCredential(username, password);

//CredentialCache mycache = new CredentialCache();

//mycache.Add(new Uri(url), "Basic", new NetworkCredential());

// myReq.Credentials = mycache;

//myReq.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(new ASCIIEncoding().GetBytes(usernamePassword)));

//HttpWebResponse b = (HttpWebResponse)myReq.GetResponse();

//Stream stream = b.GetResponseStream();

//StreamReader content = new StreamReader(stream);

WebResponse wr = myReq.GetResponse();

Stream receiveStream = wr.GetResponseStream();

StreamReader reader = new StreamReader(receiveStream, Encoding.UTF8);

string content = reader.ReadToEnd();

textBox1.Text = content + "\r\n" + textBox1.Text;