def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def current_label_end(self):
        if self.current_label and self.message:
            return self.message.get_label_range(self.current_label, self.proto_view, False)[1]
        else:
            return -1