Here's the code as it should be:
you'll need to include this as well in the same folder this code is in:
SWFObject.js
That's just some helper code, I wouldn't worry about it.
code:
<script type="text/javascript" src="swfobject.js"></script>
<div id="ytapiplayer">
You need Flash player 8+ and JavaScript enabled to view this video.
</div>
<script type="text/javascript">
var params = { allowScriptAccess: "always" };
var atts = { id: "myytplayer" };
swfobject.embedSWF("http://www.youtube.com/v/FSz_a_yx9hA&hl&enablejsapi=1&playerapiid=ytplayer",
"ytapiplayer", "425", "356", "8", null, null, params, atts);
function onYouTubePlayerReady(playerId) {
ytplayer = document.getElementById("myytplayer");
ytplayer.mute();
}
</script>
Ok I tested that code and I know it works so if you have any problems let me know, happy hacking!
Get the docs here: YouTube Embedded Player Javascript API Reference