Youtube API

HTML

<script src="http://www.bobbyvandersluis.com/swfobject/testsuite_2_2/swfobject.js"></script>
<div id="ytapiplayer">
    You need Flash player 8+ and JavaScript enabled to view this video.
  </div>
<div>
 <a id="play" href="#">Play</a>
</div>
<div class="thumbs">
</div>

JavaScript

var related = ['E6MtPshx2Ck', 'QmDVTPjmkTY', '3N1SsKd8fgI'];
for(var i=0, iMax = related.length; i<iMax; i++)
{
    $('.thumbs').append('<img src="//i2.ytimg.com/vi/'+related[i]+'/default.jpg" />\n');
}
var params = { allowScriptAccess: "always" };
var atts = { id: "myytplayer" };
swfobject.embedSWF("http://www.youtube.com/v/E6MtPshx2Ck?enablejsapi=1&playerapiid=ytplayer", 
                       "ytapiplayer", "320", "240", "8", null, null, params, atts);
var ytplayer;
function window.onYouTubePlayerReady(playerId)
{
      ytplayer = document.getElementById("myytplayer");
        alert('youtube player ready!');
}

$('#play').click(function()
{
        play();
});
//* play
function play()
{
    
  if (ytplayer) 
  {
      alert('we can play it!');
    ytplayer.playVideo();
  }
    else
        alert(ytplayer);
}