javascript - Tracking a users progress during a test/form submission -

i have form/test 20 fields users fill out. user chooses course, enters personal info along test want take. after answer 20 true , false questions , submits answers. coldfusion calculates score , stores score , user information in database.

the problem facing due poor user input missing data. users not submitting test , wonder why not in report. need come solution track users progress , logs it. don't need detailed looking see if attempted take test or not. solution have table in database 2 boolean columns. 1 true when user enters , other true when exit. record if user has entered form without submitting properly. identify reporting errors in fact user errors.

i can't seem think of other way , wanted others inputs of how handle task.

one way can think of use ajax or jquery.

on every click in input box, update counter. (you may use keypress() method) http://api.jquery.com/keypress/

when user leaves input box, check if field empty. if yes, keep counter updated. if not, decrement counter.

send final counter value used wish.