YAHOO.util.Event.onAvailable('all', function(ev) {
    var videos = YAHOO.util.Dom.getElementsByClassName('ytembed');
    YAHOO.util.Dom.batch(videos, function(element) {
        var so = new SWFObject("http://www.youtube.com/v/"+element.getAttribute('id'), "youtube", "425", "350", "7");
        so.write(element.getAttribute('id'));
    });
})