Trigger which changes values in another table

Hey all,

I'd like to create a trigger when, upon inserting a record in one table (Reservation), changes the value of an attribute in another table (Flight). I want to do this so that when a flight reservation is made, I can decrement the number of seats available for that particular flight.

What I've come up with so far is:

CREATE TRIGGER decr_on_reserve AFTER INSERT ON Reservation
FOR EACH ROW BEGIN
UPDATE Flight SET Flight.available = Flight.available - 1 WHERE Flight.fid = NEW.rfid;
END;

That is not correct, but I've googled around and haven't found any useful resources yet. Any ideas?