A generic button that calls an (argumentless) function
The generic button is implemented in FunctionCallerButton.jsas an abstract class.
In order to use it you derive buttons. The example has a confirm button and a discard
button that are activated/deactivated every 5 seconds.
Clicking an active button only opens an alert showing either CONFIRM or DISCARD.
Creating other buttons and putting the example ones to actual use should be quite straightforward.