Calculated field

[Ciprian]

Hi, i have a report that shows the status of queried contracts. One of the field shows the amount the client still has to pay, which it does by calculating the difference between the invoice amount and the amount payed. The problem i'm having is that the calculated field does not know how to take into account when 2 or more payments have been done for the same invoice amount.

I attached the db and an example. I guess i need some vba help here.

thanks

 

[Ciprian]

managed to do it with this

=[fiCost]-Sum([fipAmount])