Dynamic Menus

Okay...so far I am doing okay. I managed to set up my menus dynamically. I have four (4) different categories of menu choices. I managed to get them to dynamically pick out the subcategories of menus. However, I am having issues while clicking on the subcategories. I am using data assist and have the tables set up.

What do I need to do to show the products that are under a subcategory. I want the customer to click on subcategory menu and see a list of products listed under that subcategory. I am not sure what to do here. Right now, when I click a subcategory menu, I keep getting the same search results (when I use the search page). In other words, no matter what subcategory I choose, it shows the most recent search results. Here is what I am linking the menu to (dynamically): /product_results.php?productsubcategoryID=[productsubcategoryID]

That is wrong I am sure.

I have created data assist pages for searching products (product_results.php, product_details.php & product_search.php). Do I need to create a data assist page that lists out the products? I am clueless here. Does eCart come into play here?

I am trying to do everything dynamically, since client has a lot of products to list.