>>Ok, found it. The checkbox has caption none... :) So, I coded "visual clue" by myself in GotFocus (backcolor = rgb(0,0,64) and in the lostfocus - restore it to default)
>
>The question is: is it possible to do without changing checkbox class and without changing each instance of the checkboxes?

*-- in pseudo code
for each oControl in ThisFormsControlsRecursively
   if oControl.baseclass="checkbox"
      Bindevent(oControl, "gotfocus", this, "paintcheckboxblue") 
      Bindevent(oControl, "lostfocus", this, "paintcheckboxneutral") 
   endif
endfor