lock test question in html

I'm publishing a course to html and would like to lock a test question after the learner has answered the question. I've placed a transparent box over the question after the learner has revealed the feedback text, and eliminated the back button, but the learners are using the back button in the browser to make a second attempt on the question. I've tried opening the test in another window but upon closing, it reverts back to the last page in the chapter rather than going to the home page. Any ideas?I'm publishing a course to html and would like to lock a test question after the learner has answered the question. I've placed a transparent box over the question after the learner has revealed the feedback text, and eliminated the back button, but the learners are using the back button in the browser to make a second attempt on the question. I've tried opening the test in another window but upon closing, it reverts back to the last page in the chapter rather than going to the home page. Any ideas?