Sorry about the confusion, you do need to use quotes instead of square brackets.  You also should be using the name field instead of the filename.  Finally, there are supposed to be some paranthesis that I left out.  Try this:

ALTER DATABASE spa0822803380569
MODIFY FILE (
    NAME = 'spa0822803380569',
    MAXSIZE = UNLIMITED)

Hope that helps,

 I was afraid that might be the case.  If you're seeing that EventLog is the main culprit in your database being too large, then it may work to clean it out.

If you're comfortable doing so, you can run the following SQL to remove all entries from the Event Log:

TRUNCATE TABLE EventLog

As Alex mentioned, it's best to backup your database before doing something like this.

Hope it helps,

Glad you were able to get your site up again!

That table is used by DNN's search.  So, if you are using the built-in search within your site, you will need to leave that table as it is.  If you aren't using search, you can disable the SearchEngineScheduler entry on the Host->Scheduler page, and then clear out that table.

Hope it helps,