Restricting Access

[Chirriras]

I have a very small database associated with a web page. With FMP 6 and CDML everything works well except one thing. At the beginning of the page I ask them to click a box stating that they have completed and returned the necessary forms. If this box is not clicked, I want a message to come up telling them they have to click the box, and not allow them any access to the other fields until that one box is checked.

I haven't been able to figure out how to do this. I've tried several things, but nothing works. This would be similar, I guess, to having to click the box stating that you accept the terms of a site before you can go farther. Any clues?