Hi Siva,
Each Frontend button should be captured and triggering an event in UI Component. Do you see any event getting triggered?
You can put Breakpoint in DO_HANDLE_EVENT & see if the Event is getting captured.
Also, Check the Button Defintion (may be in DO_PREPARE_OUTPUT). Is there any event associated with the button which should get triggered.
Please check this places and if the event is getting triggered, check out the logic in event.
Thanks,
Ravi