How do I change the way to exit an experiment? (case 686)

I want to change the way to exit out of a MediaLab experiment so that participants cannot access the rest of the computer after the experiment is over. For example, instead of being able to click "OK" in the "Let your experimenter know you're finished" message, you have to hit Ctrl+Esc or something like that. Is there a way to edit the program in order to enable that?

One way to achieve what you describe would be to put a final instruction screen, and then use the "x" parameter to password protect it. That way, participants will not be able to move beyond that screen (assuming you don't tell them the password). Would that work as a solution?