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

In my case this was a shopping order. So what I did was disable the button. When the user clicked back, the button was disabled still. When they clicked back one more time, and then clicked a page button to go forward. I knew their order was submitted and skipped to another page.

In the case when the page actually refreshed which would make the button (theoretically), available; I was then able to react in the page load that the order is already submitted and redirect then too.