function yt_link_embed($yt_link, $width = 425, $height = 349)
{
	$key = substr(str_replace('http://www.youtube.com/watch?v=','',$yt_link), 0, 11);
	$return = '<iframe width="'.$width.'" height="'.$height.'" src="http://www.youtube.com/embed/'.$key.'" frameborder="0" allowfullscreen></iframe>';
	return $return;
}
//example of calling function
yt_link_embed('http://www.youtube.com/watch?v=p-QotWyPynA');

This is a simple example for new embed code of youtube from youtube link.