How can I stop the browser back button using JavaScript?

Question

I am doing an online quiz application in PHP. I want to restrict the user from going back in an exam.

I have tried the following script, but it stops my timer.

Answer 1

You can just put a small script and then check. It won't allow you to visit previous page.

This is done in JavaScript.

The window.onunload function fires when you try to visit back or previous page through browser.