RSVP Form with multiple conditioned pages and access code

RSVP Form with multiple conditioned pages and access code

I'd like to set up an RSVP form which initially lets users input a couple entries (their name and whether they're attending). At the bottom of this page I'd like them to enter a code so that I can verify only the people who have been invited are rsvping. If they enter the code wrong it shouldn't let them submit the form. If they enter the code correctly, I want them to be directed to a second form that is conditioned on their answer to whether they're attending. Is this possible? Thank you!!!