static public string xmldocumenttostring(ref xmldocument doc)
        {
            memorystream stream = new memorystream();
            xmltextwriter writer = new xmltextwriter(stream, null);
            writer.formatting = formatting.indented;
            doc.save(writer);

            streamreader sr = new streamreader(stream, system.text.encoding.utf8);
            stream.position = 0;
            string xmlstring = sr.readtoend();
            sr.close();
            stream.close();

            return xmlstring;
        }