How to validate size and color selection

I'm trying to validate that a size and color were selected before sending the item purchase to the shopping cart.

I've tried using the WebAssist Validation Toolkit and also writing my own validation code once the form reaches the eCart, but have had no luck with either. The item is just added to the cart without a size or color.

Apparently the eCart is not receiving the data as a form field, so that I can't validate that way. It must go into an array and I can't seem to figure out how to validate.

One of the issues is that not all items have a size and color selection, so that the validation must include an if/then statement (if the form.field exists, then validate it)

Using CF8, Dreamweaver CS3 and latest version of eCart and ValidationToolkit