Catch ENTER event on SELECTION SCREEN to checked change radio button depend on a PARAMETER value

Requirement: catch changing Plant value -> ENTER

If Plant value is not empty then checked radio button Data: GPRO

Else checked radio button Data: MatDoc

Logic:

AT SELECTION-SCREEN.
IF p_werks IS NOT INITIAL.
CLEAR rb_md.
rb_gpro = ‘X’.
ELSE.
CLEAR rb_gpro.
rb_md = ‘X’.
ENDIF.