HELP ! Proper Implemetation of a WHEN-RADIO-CHANGED TRIGGER

Hi Pros !
[Quoted] [Quoted] Can anyone tell me how to implement a WHEN-RADIO-CHANGED Trigger. Trying to implement a radio group and need to do somthing if a certain button has been selected. I'm not sure if the trigger should be on the button or on the group. Tried to attach one to a button and it won't work. Could not find any samples in the help file. Can anyone supply some sample code llike  

      IF  Radio_1 is selected then
     Message (' Radio 1 selected');
                task code here

    ELSE IF Radio_2 is selected then
     Message ('Radio 2 is selectd');        
                task code here

    ELSE IF  'Radio_3 slected  then
       Message ('Radio 3 is selected');
                task code here

---

END;

Do I need get_radio_button_property  ?

Thanks for your help.

Jens

jens_at_deutschware.com