window.onbeforeunload没有在Chrome中显示消息

Question

I'm showing an alert message on certain conditions when an user tries to leave. The message is shown in Safari, but it doesn't work in Chrome.
I tried two things like following:

window.onbeforeunload = function(event) {
    if ($scope.isFormChanged == true) {
        event.returnValue = 'Don\'t go yet! Save your changed data before you leave!';
    }
}

    window.onbeforeunload = function() {
        if ($scope.isFormChanged == true) {
            return 'Don\'t go yet! Save your changed data before you leave!'
        }
    }

Answer 1

I think this works in chrome. And I have also doubt with isFormChanged.

<script type="text/javascript"> window.onbeforeunload = function() { return "Are you sure you want to close window?" } </script>