code: def getNamespace(self, prefix):
          
          namespace = None
          if prefix == 'xmlns':
              namespace = DOM.findDefaultNS(prefix, self.__node)
          else:
              try:
                  namespace = DOM.findNamespaceURI(prefix, self.__node)
              except DOMException, ex:
                  if prefix != 'xml':
                      raise SchemaError, '%s namespace not declared for %s'\
                          %(prefix, self.__node._get_tagName())
                  namespace = XMLNS.XML
          return namespace
docs: prefix -- deference namespace prefix in node's context.
             Ascends parent nodes until found.