This external routine sets the numbers of the PICT resources to be used by default for displaying the buttons of type %bp_Button or %bp_RadioButton.
Parameter 1:
The name of the external area of the button.
Parameter 2:
The ID of the PICT resource of the unclicked button.
Parameter 3:
The ID of the PICT resource of the clicked button.
If you pass a negative value to one of these parameters, the existing value will not be modified.
Parameter 4:
The ID of the inactive button. If you pass 0, the inactive button will not be respresented. If you pass -1, the button will be displayed inverted. If you pass a value less than -1, the existing value will not be modified.