I can see what you are saying, but after I find the list of bookings for the week specificed with 'wk_com = ?' I only also need to find the entries where 'wk_com<?'.
Then I could use the count.
The trouble is that if I go straigt for 'wk_com<=?' then I also get the entries that do not have a booking for the specificed week.
I have been told I need to do a sub query, but I have never done one of these and wouldn't really know where to start.