Phil,
In your last db, get the query for the report in design view.
Look for the criteria (not from the booking table), but from
the charge table.
In the Column where is says ChargeID, change it to Booking
Sheet Number AND remove the criteria.
The nice way that you have your relationships set up means
that all you needed when you defined a Booking Number on
the form, all you had to do was to drag the other two tables,
cars and charges, into the query. Access made the links and
will retrieve the right records.
Relax, you're working too hard.
Wayne