function runVid(){
  if (flvjs.isSupported()) {
      var videoElement = document.getElementById('videoElement');
      var flvPlayer = flvjs.createPlayer({
          type: 'flv',
          url: 'https://stream.nannal.com/live/flag.flv'
      });
      flvPlayer.attachMediaElement(videoElement);
      flvPlayer.load();
      flvPlayer.play();
      var vid = document.getElementById("videoElement")
      vid.style.display = "block";
  }
}

function wave(){
  let promise = fetch('/wave')
}