196953 Access 2007 Project

Hello there, i have created a database with some forms in Access 2007 and the problem i have is the following. I have 3 tables with the following fields Categories [login to view URL] / Categories Products [login to view URL] / Product / [login to view URL](lookup field) This means that every product belongs to a category, in other words every value in the table products is linked with one value from the table Categories! The third table is Listings [login to view URL] / Listing_Title / [login to view URL] (Listing_Categories, which is a combo box allowing more than 1 value from the categories table) / [login to view URL] (Products, which is a combo box allowing more than 1 value from the products table) After the structure of the database i ll describe it to you in order to make it more clear what i want. I want to be able to insert new records in the Listings table and for every listing to be able to choose many categories from the combo box, and in the product combo box filter only the products that belong to the categories i have chosen for this record. Let me give you a small example... In a new record i select 2 categories from the combo box of categories, which are Football & Basketball. I want in the products field to filter and bring, as availiable to choose, only the records that refer to these 2 categories. I suppose that this operation can be controled in the form controls and not in the database structure. So i need someone to be able to handle the form controls in order to do this relation between controls. :) Finally i have attached the database that i have described to make it easier to understand the project. Please ask me for any questions