https://warringtontownfc.co.uk/js/fullscreen_mode.js

1/* View in fullscreen */
2function openFullscreen(elem) {
3  if (elem.requestFullscreen) {
4    elem.requestFullscreen();
5  } else if (elem.webkitRequestFullscreen) { /* Safari */
6    elem.webkitRequestFullscreen();
7  } else if (elem.msRequestFullscreen) { /* IE11 */
8    elem.msRequestFullscreen();
9  }
10}
11
12/* Close fullscreen */
13function closeFullscreen(elem) {
14  if (document.exitFullscreen) {
15    document.exitFullscreen();
16  } else if (document.webkitExitFullscreen) { /* Safari */
17    document.webkitExitFullscreen();
18  } else if (document.msExitFullscreen) { /* IE11 */
19    document.msExitFullscreen();
20  }
21}