javascript - How to use JS/jquery to confirm when navigating away from page

Question

I am trying to give an alert confirm dialog box when users try to navigate away...I have the following code but it doesn't quite work...

    jQuery(window).unload(function() {
        var yes = confirm("You're about to end your session, are you sure?");
        if (yes) {
            return true;
        } else {
            return false;   
        }
    });

The popup comes up fine but when I click "NO", it still navigates away...

Thanks for looking...

Answer 1

No need for JQuery:

window.onbeforeunload = function() {
    return "You're about to end your session, are you sure?";
}

Demo: http://jsfiddle.net/AlienWebguy/4fNCh/