Calculations and Value lists

[samson]

I have a database for tracking invoices. There are invoices, puchase orders and payment tables and once the invoice has been registered the invoice number shows up in a value list within the purchase order table. Once an invoice is paid it is marked as such in the payment table by selecting the invoice number and a radio button. What I would like is for the invoice value list in the purchase order table and payment table to only show the invoices which are still to be paid.

Can anyone help?

Thanks

[sbg2]

In the Purchase Order table create a global Calcualtion(result is text) field - g_InvPaid = "<InsertYourFlagHere>". Relate the two tables, PurchaseOrder::g_UnPaid <not equals symbol> Invoice::PaidStatus (Replace PaidStatus with whatever field you use to mark invoices paid), then base the Value List on related records from this table occurence showing only related records.