How to retrieve data of a product which falls under two categories?

I'm using MS SQL 2000. I developing a shopping cart where on the admin side when we are inserting or updating the products, there is a chance that a single product can fall into two categories therefore i'm giving the users a option of CheckBoxList control for the categories. The checkboxlist control is Database Databinded with categories.

When a user selects couple of checkboxes, i'm storing both the categories seperated with a comma in a single field of database but then when i want retrieve the all products of a particular category, this approach wont work. Is their any way around for this??

Even though i use CheckboxList control is their any way to retrieve products of a particular category?? Can i store each checkbox text in a different row with the same product ID's in a different table and all the product info in a different table ?? I hope i made myself clear.

Thanks for your help and time in advance.

Can anyone help me out with the above problem please??