This is a simple radio button which can be used in a form.
The instructions are in the FLA/SWF itself.
The main criteria required for flawless performance of this file is how you paste the 'off' and 'on' buttons of all the 3 sets on top of each other respectively. Otherwise there will be a jerk when the 'on button' comes on!
If you have any clarifications please do not hesitate to contact me.