Easiest solution would be to test server side if a e.g. a cookie is present and send them to the accept "form", set the cookie when they accepted.
Testing for a cookie and redirection can even be done in an apache config/.htaccess using mod_rewrite. The "form" doesn't need to process much just set the cookie, and that too can be done using mod_rewrite
So you can get it done with just mod_rewrite and a few static pages without scripting at all.