Deleting rows in table based on linked criteria

[blinder]

Hi Experts...
URGENT REQUEST FOR HELP
Version mySQL 3.23.51-nt

I have two tables (a master and a slave). I want to delete rows from the slave based on criteria in the master.

I tried updating the slave table with a value so that I could then use that value to delete from slave where value='DELETE'
I know that the delete from more than one table is coming in version 4 - but that doesn't help me now
The update doesn't work
E.g.
UPDATE slave INNER JOIN master ON slave.MasterID = master.MasterID SET slave.delete = "DELETE"
WHERE (((master.FinancialPeriod)="2003Week22&quot);

Any help will do...

Blinder