function doCopy(copy, original) {
			var value, key;

			for (key in original) {
				value = original[key];
				if (value && typeof value === 'object' && value.constructor !== Array &&
						typeof value.nodeType !== 'number') {
					copy[key] = doCopy(copy[key] || {}, value); // copy

				} else {
					copy[key] = original[key];
				}
			}
			return copy;
		}
Get the cumulative offset relative to the top left of the page. This method, unlike its
jQuery and MooTools counterpart, still suffers from issue #208 regarding the position
of a chart within a fixed container.