private function skip( $nav )
	{
		if ( $this->excludeComments && $nav->getNodeType() == XML_COMMENT_NODE )
		{
			$this->commentsSkipped++;
		}
		return	( $this->excludeComments && $nav->getNodeType() == XML_COMMENT_NODE ) ||
				( $this->excludeWhitespace && $nav->IsWhitespaceNode() );
	}