Help with a Double Booking System

[Neuojin]

Hi I am currently making a system for a church which allows them to
book out the church for a certain service for the day.

The problem is that I cannot get the Double Booking to work. I want to
make sure that the BookingDate field does not have the same date in 2
records. The simple way to solve this I have found is not to allow
duplicates in the field.

I have seen some solutions to the Double Booking system using tables
and queries, I have also been shown some code which I couldn't get
working. I was wondering what solution I should do?

Thanks for any help.

 

[Guest]

Determining wheter a booking for a date already exists is pretty simple using
the DLookup function.

If IsNull("[BookDate]", "BookingsTable", "[BookDate] = #" _
& Me.txtBookingDate & "#") Then
'If null is returned the date is opened
'If it returns the date, the date is booked.