NeoBook DB - Inventory System/POS

[radz123]

Hi i used neobook db to cfeate product listings in a table..
i was able to do just that but I wondered how to properly implement POS system

so heres what i did

created TWO databases
1. ProductList DB - store all products, prices and quantity
2. SalesTemp DB -temporary DB to Add listed items for a sale..

heres what ive done so far
added
search field for product db
shows the product in a Combo Box
Combo Box when selected will ask for Quantity then adds to SalesTemp DB
SalesTemp DB will show all the items about to be sold
I can purge the SalesTemp when new customer comes in or after confirming sale generating invoice

now heres where I am stuck

how can I deduct the Quantity from ProductList DB with SalesTemp DB?
how can I import the product price from ProductList DB to SalesTemp DB?
how can I multiply each item quantity to reflect the right Price to be paid?

if u hv a sample pub I can study or if u cn point me to the right direction..

thanks alot