How to capture browser close event?

Question

I want to capture the browser close event in my application and show a confirm box to user. I am using JSF 2.0 and richfaces 4.0.

Answer 1

Use the beforeunload event.

window.onbeforeunload = function(event) {

    event = event || window.event;

    var confirmClose = 'Are you sure?';

    // For IE and Firefox prior to version 4
    if (event) {
       event.returnValue = confirmClose;
    }

    // For Safari
    return confirmClose;

}

Keep in mind this will be fire for other events besides closing the window, such as reloading and form submission.