I'm trying to set up a page where I can have visitors use a series of checkboxes to select the products they want and then post them to checkout. I've managed to get the cart to recognize all of the purchases using numbered products_id form fields. However, the products I'm offering are delivered digitally, and although each product has only one attribute name and value (i.e. a single file) associated with it, the cart doesn't automatically associate the download with the product name when I post it. As a result, if I go to checkout, even though I've selected a number of digital products, the cart doesn't give me the option of downloading anything (I know there are other settings that could cause the same behavior, but I've tested using the standard zen cart interface and the digital products get delivered normally). I realize that zen normally uses the id[] field to determine which attributes/downloads have been selected, but it seems that field only works when posting a single product request at a time. So, does anyone know either how to post attributes for multiple products to zen, or how to get zen to automatically assign a download to a product even if the user hasn't selected it?

Thanks,
Josh