function updateHTML(elmId, value) {
        if (elmId) {
            document.getElementById(elmId).innerHTML = value;
        }
    }

    function setytplayerState(newState) {
      updateHTML("playerstate", newState);
    }

    function onYouTubePlayerReady(playerId) {
      ytplayer = document.getElementById(playerId);
      setInterval(updateytplayerInfo, 250);
      updateytplayerInfo();
      ytplayer.addEventListener("onStateChange", "onytplayerStateChange");
      ytplayer.addEventListener("onError", "onPlayerError");
    }

    function onytplayerStateChange(newState) {
      setytplayerState(newState);
    }

    function onPlayerError(errorCode) {
      alert("An error occurred: "+ errorCode);
    }

    function updateytplayerInfo() {
      updateHTML("bytesloaded", getBytesLoaded());
      updateHTML("bytestotal", getBytesTotal());
      updateHTML("videoduration", getDuration());
      updateHTML("videotime", getCurrentTime());
      updateHTML("startbytes", getStartBytes());
    }

    // functions for the api calls
    function play() {
      if (ytplayer) {
        ytplayer.playVideo();
      }
    }

    function pause() {
      if (ytplayer) {
        ytplayer.pauseVideo();
      }
    }

    function stop() {
      if (ytplayer) {
        ytplayer.stopVideo();
      }
    }

    function getPlayerState() {
      if (ytplayer) {
        return ytplayer.getPlayerState();
      }
    }

    function seekTo(seconds) {
      if (ytplayer) {
        ytplayer.seekTo(seconds, true);
      }
    }

    function getBytesLoaded() {
      if (ytplayer) {
        return ytplayer.getVideoBytesLoaded();
      }
    }

    function getBytesTotal() {
      if (ytplayer) {
        return ytplayer.getVideoBytesTotal();
      }
    }

    function getCurrentTime() {
      if (ytplayer) {
        return ytplayer.getCurrentTime();
      }
    }

    function getDuration() {
      if (ytplayer) {
        return ytplayer.getDuration();
      }
    }

    function getStartBytes() {
      if (ytplayer) {
        return ytplayer.getVideoStartBytes();
      }
    }

    function mute() {
      if (ytplayer) {
        ytplayer.mute();
      }
    }

    function unMute() {
      if (ytplayer) {
        ytplayer.unMute();
      }
    }