Hi,
You have to make a radio button as default and add a user command to it.Please refer the below code for the changes made.
SELECTION-SCREEN : BEGIN OF BLOCK b1 WITH FRAME TITLE text-001.
PARAMETER : p_code RADIOBUTTON GROUP rdbDEFAULT 'X' USER-COMMAND cmd,
p_pono RADIOBUTTON GROUP rdb.
SELECTION-SCREEN END OF BLOCK b1.
SELECTION-SCREEN : BEGIN OF BLOCK b2 WITH FRAME TITLE text-002.
SELECT-OPTIONS : s_ccode FOR WA_ekko-bukrs MODIF ID cod,
s_pono FOR WA_ekko-ebeln MODIF ID pon.
SELECTION-SCREEN END OF BLOCK b2.
AT SELECTION-SCREEN OUTPUT.
LOOP AT SCREEN.
IF p_code = 'X'.
IF screen-group1 = 'PON'.
screen-input = '0'.
ENDIF.
ELSEIF p_pono = 'X'.
IF screen-group1 = 'COD'.
screen-input = '0'.
ENDIF.
ENDIF.
MODIFY SCREEN.
ENDLOOP.
Regards,
Jeffin