            bool firstLoop = true;
            string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}";
            foreach (string key in nvc.Keys)
            {
                if (firstLoop)
                {
                    rs.Write(boundarybytesF, 0, boundarybytesF.Length);
                    firstLoop = false;
                }
                else
                {
                    rs.Write(boundarybytes, 0, boundarybytes.Length);
                }
                string formitem = string.Format(formdataTemplate, key, nvc[key]);