Expression Forumula Help

Thank you Anthony

Yes I copied that out of a forum, and can't get it to do what I need.

What I'm trying to do, is work out how long the item has been listed for?

They get a charge for each week the item is relisted, up to 3 weeks (then the item is returned if unsold).

But the calculation field I have, is in days.

So I want to see if its less than 7 days, its zero, but if its 7, 14 or 21, they get a fee (£1.20) of 1.20, 2.40 or 3.60.

Also, I am going to need to be able to select items to be invoiced (where they calculations fields will be picked up and form an invoice), I'm not quite sure how to do that?

Can I store the invoices per customer, so if a customer comes in, they can show them what they've been paid for, when, what invoice number, and I can show them which items are outstanding (not been invoiced for yet)

I do want to pull VBA in, but want to get the nuts and bolts working first.

Thanks so much
Clair