1.3.0 2016/03/30 - Support Buy Now buttons with up to three Option dropdowns or text fields.
1.2.0 2015/10/23 - Grouping of parameters. Improved debug information in html comments. Allow custom paypal.com site specification for testing. Workaround for transactions missing gross payment.
1.1.1 2015/09/20 - Minor update of tags for organizing Stacks.
1.1.0 2015/05/05 - Convert transaction id to uppercase before confirming with PayPal. Consider the Item ID (item_number in URL) as case insensitive.
1.0.0 2015/01/12 - Initial release of PayPalStack stack.
PayPalStack: Easily handle PayPal Buy Now purchases with this Stack. PayPalStack takes transaction information from PayPal, validates purchases, then displays any Stacks you have chosen on success. It can display another set of Stacks on failed transactions. Great for selling downloadable content like eBooks, music, apps, etc.