Below is the code I am using ... I am not sure if this is right.


int debug = 1; // 1 = true
            string debugEmail = "erald@ghanafx.com";
            StringBuilder data = new StringBuilder();
            data.Append("oid=[00D20000000l2qZ]");
            data.Append("&retURL=" + HttpContext.Current.Server.UrlEncode("https://secure.ghanafx.com/open-live-account-thanks"));
            data.Append("&first_name=" + HttpContext.Current.Server.UrlEncode("Mohsin"));
            data.Append("&last_name=" + HttpContext.Current.Server.UrlEncode("Ali"));
            data.Append("&email=" + HttpContext.Current.Server.UrlEncode("mohsin_ali_nisar@yahoo.com"));
            data.Append("&country_code=" + HttpContext.Current.Server.UrlEncode("AX"));
            data.Append("&00N0O00000ALjKl=" + HttpContext.Current.Server.UrlEncode("50"));
            data.Append("&00N0O00000ALj57=" + HttpContext.Current.Server.UrlEncode("S/E"));
            data.Append("&00N0O00000ALj52=" + HttpContext.Current.Server.UrlEncode("7PM"));
            data.Append("&00N0O00000ALj4n=" + HttpContext.Current.Server.UrlEncode("Expert"));
            data.Append("&mobile=" + HttpContext.Current.Server.UrlEncode("03319337096"));
            data.Append("&phone=" + HttpContext.Current.Server.UrlEncode("05453534"));
            data.Append("&title=" + HttpContext.Current.Server.UrlEncode("MOSS"));
            data.Append("&debug=" + debug);
            data.Append("&debugEmail=" + HttpContext.Current.Server.UrlEncode(debugEmail));
            // Post the data
            byte[] buffer = Encoding.UTF8.GetBytes(data.ToString());
            string url = "https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8";
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";
            buffer = Encoding.UTF8.GetBytes(data.ToString());
            req.ContentLength = buffer.Length;
            using (Stream reqst = req.GetRequestStream())
            {
                reqst.Write(buffer, 0, buffer.Length);
                
            }