Thanks in advance for your help.
I have a contact form made through Contact Form 7 with a checkbox that has the options of "Yes" or "No". If someone checks "No", I want to be able to display a pop-up (whether within the page or physically a pop-up - doesn't matter) that has additional text that says "STOP. Blah blah blah..." so that the person knows to stop filling out the form because of their response in the checkbox.
I haven't been able to figure out how to do that, or what to search for, so I have created this new topic to ask for help.