[xml] problem using libxml schema validating

["Liu Jianxin, NY" <jianxin liu fja-us com>]

libXml Group:
I am trying to use xmlschema (libxml2-2.4.22) to valid the xml file, but it
gave me some message:
===========================================
Unimplemented block at ..\xmlschemas.c:2918
Unimplemented block at ..\xmlschemas.c:2918
Unimplemented block at ..\xmlschemas.c:2922
===========================================

The code I called the xmlschema validator:
==========================================
string url = "c:/sample.xsd";
xmlSchemaParserCtxtPtr schemaParserCtxtPtr =
xmlSchemaNewParserCtxt((char*)url.c_str());
xmlSchemaPtr schemaPtr = xmlSchemaParse(schemaParserCtxtPtr);
xmlSchemaValidCtxtPtr schemaValidCtxtPtr = xmlSchemaNewValidCtxt(schemaPtr);
int valid = xmlSchemaValidateDoc(schemaValidCtxtPtr, doc); //doc is
xmlDocPtr
==========================================

Has anybody got same problem? And How do I solve this problem?
Thanks!
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