weizman/cancelable-beforeunload-event-demo.js

## cancelable-beforeunload-event-demo.js
// by https://developer.mozilla.org/en-US/docs/Web/Events/beforeunload#Example
window.addEventListener("beforeunload", function (event) {
  event.preventDefault(); // Cancel the event as stated by the standard.
  event.returnValue = ''; // Chrome requires returnValue to be set.
});
	// by https://developer.mozilla.org/en-US/docs/Web/Events/beforeunload#Example
	window.addEventListener("beforeunload", function (event) {
	event.preventDefault(); // Cancel the event as stated by the standard.
	event.returnValue = ''; // Chrome requires returnValue to be set.
	});