Minimize/disappear an button-object, when chart-object is minimized

[#1]

Hi Guys,
this is probably an easy question, but I just cant figure it out!

My intention is to minimize a chart-object. In the same moment a button-object should disappear. When I restore the chart, the button should appear.

The code could be something like this:

if ( IsMinimized( chartobjekt123 ), , )

writen into the button-objekts visibility-requirement (Layout)!

Any Ideas??

Thanks!