$.ui.plugin.add("draggable", "alsoDrag", {
	start: function() {
		var that = $(this).data("ui-draggable"),
		o = that.options,
		_store = function (exp) {
			$(exp).each(function() {
				var el = $(this);
				el.data("ui-draggable-alsoDrag", {
					top: parseInt(el.css("top"), 10),
					left: parseInt(el.css("left"), 10)
				});
			});
		};

		if (typeof(o.alsoDrag) === "object" && !o.alsoDrag.parentNode) {
			if (o.alsoDrag.length) { o.alsoDrag = o.alsoDrag[0]; _store(o.alsoDrag); }
			else { $.each(o.alsoDrag, function (exp) { _store(exp); }); }
		}else{
			_store(o.alsoDrag);
		}
	},
	drag: function () {
		var that = $(this).data("ui-draggable"),
		o = that.options,
		os = that.originalSize,
		op = that.originalPosition,
		delta = {
			top: (that.position.top - op.top) || 0, 
			left: (that.position.left - op.left) || 0
		},

		_alsoDrag = function (exp, c) {
			$(exp).each(function() {
				var el = $(this), start = $(this).data("ui-draggable-alsoDrag"), style = {},
				css = ["top", "left"];

				$.each(css, function (i, prop) {
					var sum = (start[prop]||0) + (delta[prop]||0);
					style[prop] = sum || null;
				});

				el.css(style);
			});
		};

		if (typeof(o.alsoDrag) === "object" && !o.alsoDrag.nodeType) {
			$.each(o.alsoDrag, function (exp, c) { _alsoDrag(exp, c); });
		}else{
			_alsoDrag(o.alsoDrag);
		}
	},
	stop: function() {
		$(this).removeData("draggable-alsoDrag");
	}
});