title: Restrict user to refresh and back,forward in any browser
body: <p>I am working on an evaluation system, In which candidate attempt for an exam. So the page where a question and its choices are get rendered is a page with <code>iframe</code> , In that questions are get the render. The page which holds <code>iframe</code> contains <code>JavaScript</code> timer.</p>
  
  <p>So when questions get render on the browser to restrict refresh I have written <code>F5</code> and <code>ctrl+F5</code> blocking code so candidate can't refresh using keyboard shortcuts but in a browser window, one can still use refresh button or back button. Is there any way to disable this? I know playing with browser functionality is not good practice, So is there any way to get out of this. </p>