After

Dim readStream As New StreamReader(sr, Encoding.UTF8)

Add

MessageBox.Show(webResp.StatusCode.ToString)

MessageBox.Show(webResp.StatusDescription)

MessageBox.Show(String.Join(",", Array.ConvertAll(System.Text.Encoding.UTF8.GetBytes(readStream.ReadToEnd()), Function(x) x.ToString())))

This will give you three prompts, response status, response description and ascii codes for response buffer