I found that if the customer's delivery zone is outside all available shipping zones that main_page checkout_shipping will load with no modules to select and the "continue" button does not work.

How would I replace the "continue" button with a friendly message that says something like "We're sorry, We can't ship this item to your address."?

(This is a really old cart that would give me fits if I tried to upgrade it. v1.2.1)