Using a text field to produce a Yes/No result

[RichS]

I have a table of invoices with a column for the amount and a column for when the invoice was paid (if it has been). I would like to produce two totals, one for the total amount invoiced (that bit is easy) and one for the invoices that haven't been paid. I have a third hidden column to hold the amount owed for each invoice but need to calculate this. I would like to produce a formula that will place the value of the invoice in the unpaid value when there is no paid date present. How do I do this?

 

[Husan]

a iif statement should do this:

if paid date is null then amount owed=invoice amount else amount owed=0

syntax would look somethin like this:
Amount owed=iif(isnull([Paid Date]),[Invoice Amount],0)