Add row to a table

[Paul Stan via AccessMonster.com]

Hi Wizards,
I have the following problem:
I need to add new row to the transaction detail in purchase order. To do
this I designed a form "Purchase Orders" with a subform "Transaction
Details". In the transaction the user has to add products but there are too
many of them and I need to filter them by category. For this purpose I
designed a form "Add_Product" with a subform "Add_Product_sub". This form
has an unbound combo box for the CategoryID and my subform shows me
filtered list of products. I have 2 action buttons on the form footer -
Cancel and Add. The Cancel button is easy - just close the form, but Add
button I need to connect it to an add query.
There are my problems:
1. How to handle the information about the selected record on the subform
Add_Product_sub (CategoryID, ProductID) and to add it to the Transaction
Details for the corresponding Purchase Order.
2. How to design add query using information from Purchase Order form and
Transaction Details subform to add a new row in the Transaction Details
table.

Thank you for consideration,
PS