//Create droppable playlist container
Droppables.add( 'playlist', { accept: 'draggable_element',
	onDrop:function(element) { 
		playlist.add(element.videoId);
		} 
	});

var dragObserver = Class.create();
dragObserver.prototype = {
	initialize: function() {
	},

	onStart:function(eventName, draggable, mouseEvent) {
	},

	onEnd:function() {
	}
}

var ob = new dragObserver(); 
Draggables.addObserver(ob);