Mozilla firefox not working with [removed]

Question

I\'m using window.onbeforeunload to display a message to the user on windows close, the function works well with Chrome and IE but it doesn\'t work with Firefox

Answer 1

Using the code given in the MDN works for me in firefox/chrome/IE11 (haven't try other browser for now).

window.onbeforeunload = function (e) {
  var e = e || window.event;

  // For IE and Firefox
  if (e) {
    e.returnValue = 'Any string';
  }

  // For Safari
  return 'Any string';
};

here is the doc : Mdn window.onbeforeunload doc