There are a couple different approaches that can be used for categories:
1) a product can belong to only one category
2) a product can belong to multiple categories
the basic idea for showing the products in the categopry is to create a recordset that filters the products based on the CategoryID URL Variable.
the specifics of this depend on which approach was used.
If products belong to only one category, there will be a CategoryID column in the products table, create the recordset to filter the Products table using the Category ID column and the CategoryID URL Variable.
If products can belong to more than one category, you will have a linking table and will need to use a joined query, see the following page for more details on joined queries: