I'm trying to improve a booking application I wrote a little while ago, basically the user can book a 'slot' for a light aircraft, at the moment the drop down list is populated as per the flying school booking slots ie. 09:00-10:00 , 10:00-11:00 etc right through until 21:00.

Currently it's up to the user to select a slot that hasn't been booked by cross checking the current bookings (which are always displayed), basically all the slots remain selectable from the dropdown list.

What I would like to do is modify the dropdown list so when a slot is booked it is also removed from the list to prevent future selection.

The dropdown list is not bound to the database at the moment it's been manually populated with list items. I think I will need to bind it or use the booked data from the database to modify the list in some way but not sure how as the database only contains a field called 'slot' to record the booked slot, maybe I need to add fields for each slot.

Thanks for any advice.