persisting links between tables thru forms

[iclaudius]

Newbie here - setting up my first db/php site. what fun!

I've created a php form that is supposted to:

1. post new product to table "products"
2. associate a category selected for this product to a category in table "categories" by setting a relationship between the two, entered in a third table "products_categories"

I'm using a tutorial here for the framework:
http://codewalkers.com/tutorials/37/1.html

The form is on one page - "productadd.php", which uses a class called Persistclass from another file "product_class.php"

Persistclass is extended into Product, and LinkProductCategory

While I can get the form to enter the product, the link is not made.

Any ideas for this pitiful soul?

many thanks in advance
Peter