$(".glass_container").ready(function() {
	$(".glass_container").each(function(i) {
		$(this).draggable({ zIndex: 100 });
		
		//update the background-position based upon current position
		$(this).bind("drag",function(event, ui) {
			$(this).css("left:" + ui.position.left);
			$(this).css("top: " + ui.position.top);
			$(this).css("background-position",-ui.position.left + "px " + -ui.position.top + "px");
		});
	});
});