I have a similar challenge. I'm asking the user to find a "hidden word" somewhere in a long block of text. In the form, they enter their info (name, etc.) and also the extra word they found. I either want to disable the submit button until the user has entered the correct answer, or, on submitting with the wrong answer, return the user to the form with all the other fields retaining their values. An example of my form is here: https://www.riseto.org/agree-to-rules-validate. Anyone know how do do this? Thanks!