How to completly disable back button of a browser while taking online exam?

Question

In online examination once candidate has clicks on start button i dont want to allow him to go back (to previous pages) and he should be in same page if he do any activities

Answer 1

Try in your page following function to prevent unloading of form.

$(window).on('beforeunload', function(){
      return false;
});

Or try unload function and prevent unloading of current page silently.