How to hide a submit button is a site which has information about just that...
...and in fact, ONLY about that. It lists some methods which can be used to hide the submit button in your Domino applications, even listing methods which worked with R4.6 - woo! The highlight of this site is the rather weird flashing circled 'Here' hotspots for all the different approaches, and of course the slightly predictable and semi plagurised blonde method for hiding your Submit button.