How to show the “Are you sure you want to navigate away from this page?” when changes committed?

Question

Here in stackoverflow, if you started to make changes then you attempt to navigate away from the page, a javascript confirm button shows up and asks: \"Are you sure you want

Answer 1

To make this work in Chrome and Safari, you would have to do it like this

window.onbeforeunload = function(e) {
    return "Sure you want to leave?";
};

Reference: https://developer.mozilla.org/en/DOM/window.onbeforeunload