gtk-radio-button-set-group (button group)

button -- a gtk-radio-button widget
group -- an existing gtk-radio-button group, such as one returned from the gtk-radio-button-get-group function

Sets a the group of the radio button. It should be noted that this does not change the layout of your interface in any way, so if you are changing the group, it is likely you will need to re-arrange the user interface to reflect these changes.