Subtracting from balance

[lesterd]

I have a file we are trying to use in a high school parking lot. The file tracks parking fines. I have the file adding the total of fines owed, but I want to deduct the paid fines from the running total. THe fines are listed in a portal below the ticket by means of a self joining relationship. I have attached the file for you to look at.

I guess I am looking for a formula or calculation that will deduct the paid fine amount from the current balance when an "x" is placed in the paid box.

Any help will be appreciated.

Thanks

Lester

I am using FMP 11

ParkingFines.fp7.zip

[comment]

I don't see an attached file. Try adding a calculation field =

Case ( Paid ; Amount )

where Paid is either a Number field containing 1 if the fine was paid, or - preferably, IMHO - a Date field containing the date of payment

Note that this is assuming a fine cannot be paid partially.

[No_access]

Members post should work for what you posted, however for your application you may want to consider a Balance due field or a balanced recieved , this can also let you take a partial as a student may not have enough to pay as it is.. and this will also solve your problem of totals.

[lesterd]

It now works. Thanks for the help.