Thanks again!

I already use .setImage() and .getImage() pretty often. :-)
But that did not solve the need to have all buttons pre-existing on the page. :-/

But I will take a look at the workaround with the off page-buttons, that may be a good start. So I can put all buttons on the page, but off the screen and dynamically show them by adjusting .top and .left... Sounds good...