Microsoft SharePoint Bill of Lading

Currently I have a Microsoft SharePoint WSS 3.0 site.? The site is used for tracking inventory.? The site stores customers and inventory information such as the amount and product type. Here is what I need: First the user, will fill out information necessary for the bill of lading, such as ship to, ship from, po#, etc.. Next, the user needs to be able to select from a dropdownlist the customer (which is linked to a sharepoint list), then a gridview is populated with the current products the customer has in the warehouse (these products also reside in a sharepoint list).? Next, the user is able to select a checkbox next to each product to decide which products will be added to the Bill of Lading.? When the checkbox is selected a textbox appears asking for amount of product in cases that is being shipped out.? The amount is then subtracted from the current inventory and all information inputted appears on the bill of lading with the selected inventory items and the amounts to be shipped. ## Deliverables I will be happy to provide screenshots, current BOL aspx file, and list template with current data.