Change button state programmatically

One for the JS gurus.

Can't seem to find anything on this in the forum.

Anyone know how to toggle the (visual) state of a X6 button between disabled and enabled.

I am aware that disabled/enabled here only refers to the visual state of the button and not actions, links etc.

I want a mechanism for visually enabling/disabling buttons. I can handle (I hope!) the actions side of things. It's just the visual toggle that escapes me. Looks as though some hack with X6 button styles will be needed. Not my strong suit!

Not sure how X6 can offer a disable option in the button editor with no obvious way of enabling it - unless I've missed something blindingly obvious?

Any suggestions gratefully received.

Thanks,

John B