private function checkDB() {
		$res = $this->query('select * from sqlite_master where type=\'table\' and name=\'dropbox\'; ');
		if (! $res) {
			try {
				$this->DB->exec('create table '.$this->DB_TableName.'(path text, fname text, dat blob, isdir integer);');
				$this->DB->exec('create index nameidx on '.$this->DB_TableName.'(path, fname)');
				$this->DB->exec('create index isdiridx on '.$this->DB_TableName.'(isdir)');
			} catch (PDOException $e) {
				return $this->setError($e->getMessage());
			}
		}
		return true;
	}