Convert Dataset to XML

      public string ConvertToXml(DataSet ds)
        {
            // This is the final document  
            XmlDocument Data = new XmlDocument();
            // Create a string writer that will write the Xml to a string
            StringWriter stringWriter = new StringWriter();

            // The Xml Text writer acts as a bridge between the xml stream and the text stream
            XmlTextWriter xmlTextWriter = new XmlTextWriter(stringWriter);

            // Now take the Dataset and extract the Xml from it, it will write to the string writer
            ds.WriteXml(xmlTextWriter);

            // Write the Xml out to a string
            return stringWriter.ToString();
        }