How to dynamically deactivate and activate parameters on selection screen?

Question

Hi,
I need to deactivate/activate a parameter in my selection screen whenever i clicked on a particular radiobutton. I could deactivate the parameter when the screen is first loaded using the following code,
<i>AT SELECTION SCREEN OUTPUT.
LOOP AT SCREEN.
  IF SCREEN-NAME = 'P_DATE'.
     SCREEN-INPUT = '0'.
     MODIFY SCREEN.
  ENDIF.
ENDLOOP.</i>
But I have problems capturing the event when the user click on the radiobutton, so i could activate the parameter. I did not create any screen.
Is there a way to solve this problem w/o creating a screen. If none, how do I go about it after I have created a screen for selection.
Thanks for any suggestions.

Answer 1

Hi CK,
The following code might help,
*-- Status of Screen Field (Ready/Not Ready for Input)
    fld_status   LIKE screen-input,
PARAMETERS: rbut01  TYPE char01
                    RADIOBUTTON GROUP g1
                    USER-COMMAND ucomm1     "event for radio button click
                    DEFAULT 'X'.
            rbut02  TYPE char01
                    RADIOBUTTON GROUP btyp.
Event Handler for Change of Budget Type *
AT SELECTION-SCREEN.
*-- In case user command is a budget type change (Radio Button Change)
  IF sscrfields-ucomm =  'UCOMM1'.
    IF rbut01 = 'X'.
      fld_status = '0'.
    ELSEIF rbut2 = 'X'.
      fld_status = '1'.
    ENDIF.
  ENDIF.
At Selection Screen Output *
AT SELECTION-SCREEN OUTPUT.
  LOOP AT SCREEN.
    CASE screen-name(4).
      WHEN 'FLD01' OR 'FLD02'.
*---    Changing Status of Fld01 and Fld02 Fields on Change of Radio Button
        screen-input = fld_status.
        MODIFY SCREEN.
    ENDCASE.
  ENDLOOP.