text: var media = document.querySelectorAll('video, audio');
  var rate = prompt('Speed? Currently playing back at ' + media[0].playbackRate + 'x.','');
  Array.prototype.forEach.call(media, function(player) {
     if (rate == null) {
        return;
     } else if (rate != 0) {
        player.playbackRate = rate;
     } else {
        player.playbackRate = 1;
     }
  });
  