Add prompt thats asks if you're sure if you want to reload or navigate away from the page.

[mdavoodi]

It would be nice if you've modified the file to be prompted to cancel the navigation or discard your changes before navigating away from the page (e.g. when you click the browser's back button).

An example of this behavior can be seen on JSFiddle.net if you attempt to reload the page before saving your changes:

[mdavoodi]

Theres been a second request for this.