https://www.fastnewsletters.com/wp-content/plugins/alligator-popup/js/popup.js?ver=2.0.0

1document.addEventListener('DOMContentLoaded', function() {
2
3  var popupLinks = document.querySelectorAll('.popup');
4
5  popupLinks.forEach(function(popupLink) {
6
7    popupLink.addEventListener('click', function(event) {
8      event.preventDefault();
9
10      var w = popupLink.dataset.width;
11      var h = popupLink.dataset.height;
12      var s = popupLink.dataset.scrollbars;
13
14      var left = (window.screen.width / 2) - (w / 2);
15      var top = (window.screen.height / 2) - (h / 2);
16
17      var popupWindow = window.open(popupLink.href, '', 'scrollbars=' + s + ',resizable=yes,width=' + w + ',height=' + h + ',top=' + top + ',left=' + left);
18
19      if (popupWindow) {
20        popupWindow.focus();
21      }
22    });
23  });
24});