The category results page is just a results page for a search and does not actually change for the various products. Are you talking about displaying the category for a product on the product detail page? If so you will need to get the category name for the product you are working with. If you add in an advanced recordset with this query you should get the category for the current item:
SELECT products.ProductName AS 'name', productcategories.CategoryName AS 'category'
From products, productcategories
WHERE products.ProductCategoryID = productcategories.CategoryID AND Products.ProductID =
For the ProductID portion you will need to specify your own SQL parameter and set it's value to the form value for ProductID