private string login(string url, string username, string password)
        {
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            //string cookie = "";
            string values = "vb_login_username=" + username + "&vb_login_password=" + password
                                                    + "&securitytoken=guest&"
                                                    + "cookieuser=checked&"
                                                    + "do=login";
            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";
            req.ContentLength = values.Length;
            req.Timeout = 10000;
            req.KeepAlive = true;

            CookieContainer a = new CookieContainer();
            req.CookieContainer = a;

            System.Net.ServicePointManager.Expect100Continue = false; // prevents 417 error

            using (StreamWriter writer = new StreamWriter(req.GetRequestStream(), System.Text.Encoding.ASCII))
            { writer.Write(values); }

            //HttpWebResponse c = (HttpWebResponse)req.GetResponse();
            try { this.response = (HttpWebResponse)req.GetResponse(); }

            catch (WebException ex)
            {

                MessageBox.Show(ex.ToString());
            }

            foreach (Cookie cook in this.response.Cookies) { this.cookie = this.cookie + cook.ToString() + ";"; }


            return this.cookie;
        }