I've googled for this but all I can find is create statements so I'm hoping someone can just give me a quick answer.  I'm trying to write some db creation scripts.  Normally in MSSQL I would use an if exists from the system tables to check whether or not to run a drop before creating the table.  I found the sys.systables info about derby, but I can't seem to get the if clause working for that.

IF EXISTS (SELECT * FROM sys.systables WHERE tablename='[tablename]') DROP TABLE [tablename];

Thanks in advance,