This property represents the response entity body as parsed by the MSXML XMLDOM parser.
For security
reasons, the parser validation features are always turned off to
prevent MSXML from attempting to download a DTD or XML-Data definition.
If the response entity body is not valid XML, this method returns the
Document object that was
parsed so that you can access the ParseError object through it. (Note that the
ParseError object itself is not returned; it is only accessible
through the Document object.)
If the response was generated by an ASP page, and the MIME type was
not correctly set to 'text/xml', responseXML will be empty.