javascript youtube api 및 자동재생

var tag = document.createElement('script');

tag.src = "https://www.youtube.com/iframe_api";
var firstScriptTag = document.getElementsByTagName('script')[0];
firstScriptTag.parentNode.insertBefore(tag, firstScriptTag);

var player;
function onYouTubeIframeAPIReady() {
  player = new YT.Player('player', {
	 height: '390',
	 width: '640',
	 videoId: 'HgruWmbIlq8',
	 events: {
		'onReady': onPlayerReady,
		'onStateChange': onPlayerStateChange
	 }
  });
}


function onPlayerReady(event) {
  event.target.playVideo();
}

var done = false;
function onPlayerStateChange(event) {
  if (event.data == YT.PlayerState.PLAYING && !done) {
	 setTimeout(stopVideo, 6000);
	 done = true;
  }
}
function stopVideo() {
  player.stopVideo();
}