public static XmlDocument CreateMessage(string schemaName, string rootNode, string assembly)

{

    XmlDocument doc = new XmlDocument();

    DocumentSpec docSpec;

    BtsCatalogExplorer catalog = new BtsCatalogExplorer();

    catalog.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings[BTS_CONNECTION_STRING].ConnectionString;

    Schema schema = null;

    if (assembly == string.Empty)

        schema = catalog.Schemas[schemaName];

    else

        schema = catalog.Schemas[schemaName, assembly];

    if (schema == null)

        throw new BTSUtilitiesException(string.Format("Failed to retrieve the {0} schema from the management database.", schemaName));

    else

    {             

        docSpec = new DocumentSpec(rootNode, schema.BtsAssembly.DisplayName);

        if (docSpec == null)

            throw new BTSUtilitiesException(string.Format("Failed to build the document {0}.", rootNode));

        else

        {

            StringBuilder sb = new StringBuilder();

            StringWriter sw = new StringWriter(sb);

            try

            {

                doc.Load(docSpec.CreateXmlInstance(sw));

            }

            finally

            {

                sw.Dispose();

            }                    

        }

    }

    return doc;

 }