XML and PL/SQL

I am having trouble compiling a pl/sql procedure that uses the XML Parser.

CREATE OR REPLACE procedure parse_my_dtd as
p xmlparser.parser;
l_clob clob;
begin
p := xmlparser.newParser;
select content into l_clob from dca_documents where doc_id = 1;
xmlparser.parseDTDClob(p,l_clob,'site_template');
end;
/

The error is
PLS-00201: identifier 'XMLPARSER.PARSER' must be declared

Does this mean that xdk is not installed or do I need to declare something else in the procedure.

Thanks
Tim