help with trigger

Hi folks,
I'm new to PostgreSQL and am busy tring to work with
it. Of pl/pgsql I know even less and that's the part I
have a question on right now. I have this nice example
to get me started with
pl/pgsql.......

I have a table with the schedule of a service my sport
team wants to offer:

Table Schedule
name length startdate enddate day
soccer 4 01-sep-2004 30-sep-2004 Mon
tennis 4 01-sep-2004 30-sep-2004 Wed

This means, that I want to offer soccer weekly, for a
total of 4 weeks as from 1st sep till 30 sep on
Mondays!

Now, what I do want is a second table that creates all
the dates on which there will be soccer training if I
finish entering this record in table Schedule. So,
then the other table, called ScheduledDates has the
follwing records:

Table ScheduleDates
name occurrence date
soccer 1 06-sep-2004
soccer 2 13-sep-2004
soccer 3 20-sep-2004
soccer 4 27-sep-2004

Can someone help me with writing this as a trigger in
pl/pgsql?

Another variant is that the trigger starts when the
table Schedule is populated, but it not just
automatically creates the 4 records as described
above, but because the date 20-sep-2004 is a national
holiday and is in table Exceptions, the sheme just
shifts one up and the occurrence 4 becomes occurrence
3 and the last schedule date becomes monday the 4th of
october!

I hope you can help me with this one, will put me way
up the learning curve of pl/pgsql

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