help with funtion (expression builder)

[DP]

hi,

i have a form, which shows rentals of a film. a rental; has a price code
attached to it,. e.g. a = £3.00. b = £3.50, etc...

i've got a form, with a subform at the bottom.

how can i create a field in the normal form, showing the total amount due.
I've got a text and a label.

i've got this forumula.;

=[Game Orders Subform1].Form!Price

which shows only £2.00, which is the cost of 1 of the items, how do i get it
to add all the items up, and show that, e.g. it should show £4.00,. as there
are 2 items costing £2 each

thanx

devin

[Ken Post]

Going from memory- the easiest way to do this is to put the total in
the form footer of the subform and have this be hidden.

On the subform put a field called InvoiceTotal with a formula something
like this:
=Sum(Price)

make sure that works, then set its visible property to false.

Then on the main form put a field with formula
=[Game Orders Subform1].InvoiceTotal

I believe this should work. Lemme know
Ken

[DP]

yo

that worked, but i had to put it in the actual query.
thanx anywayz.

if i had an customer, rental table, and film rental table.
and forms for each one,
when a customer rents a film, how would i stop the user, from entering the
same film id twice? (because if a film is out on rent, it cant be rented to
someone else at the same time) it cant be rented till it has came back. how
would i implement this kind of validation?
devin

"Ken Post" <nn*******@gmail.com> wrote in message
news:11*********************@o13g2000cwo.googlegro ups.com...

Going from memory- the easiest way to do this is to put the total in
the form footer of the subform and have this be hidden.

On the subform put a field called InvoiceTotal with a formula something
like this:
=Sum(Price)

make sure that works, then set its visible property to false.

Then on the main form put a field with formula
=[Game Orders Subform1].InvoiceTotal

I believe this should work. Lemme know
Ken

[Ken Post]

Simplest way would probably be to use a boolean field to track if the
item is available or not.