Is this possible:
1. User clicks add to cart link
2. I run a check to make sure everything is cool with fc_PreProcess()
3. If the check fails, I can show a notification message (of why the check failed) inside the foxybox?
Maybe (if the check fails) I could change the URL of the page being seen inside the foxybox and then return true, so the foxybox is still shown, rather than returning false and not showing the foxybox at all?