purchase order to invoice/voucher

[mdemarte]

I have an Approach database that I need to convert to Access. I need to start with a Purchase Order that may have more than one item on it. Then, when the invoice(s) come in, I need to display the items (and be able to change them) from the Purchase Order on the invoice screen with the original total from the Purchase Order items, the invoice item totals, and the difference.

Here is the layout (with only the pertinent fields):

Parent table: tblHwydlypo
main key: purchkey (autonumber)
venname
vendorno

child table: tblItempo
main key:itempokey
link to mainurchkey
item
quantity
price
shipping

child table:tblIteminv
mainkey:iteminvkey
link to mainurchkey
item
quantity
price
shipping

Example: Let's say I send out a purchase order for 2 monitors, price 500.00 apiece and shipping is 20.00. I also want a printer, and that is 1000.00 price. The invoice comes in for just the one monitor, the other stuff is delayed. I still want to show both descriptions, pick the monitor (and include the exact model#) and price of 500.00, but want to change the quantity. The shipping is 5.00 for one. I need to show the original total of 2020.00, the new total of 505.00 and the balance of 1515.00 as well.

Thanks. Sorry for the length of the posting.