Need macro to change a button's image

Using LO with OSX 10.10.3

I need a macro to change a button’s image on a form.

This method: link to forum item

does not appear to work.

I’ve dumped the properties of the button object and

the Graphic property of a button is not exposed and

therefore does not appear to be able to be addressed or changed

I got the answer to this problem by asking this question

what is the base ide equivalent of Thiscompnent