Need HELP IN CHECK box in alv

Hi All,

i have a small query .

i have kept a checkbox in my selection screen when i check that check box and press enter . 2 parameters are getting default values

which is fine.

now my requirement is when i check the checkbox without pressing the Enter button i need to populate the default values .

please see the attached doc with screenshots and the code i have written ..

IF cb_adw IS INITIAL.
LOOP AT SCREEN.
IF screen-name = 'P_AFFIL' OR
screen-name = 'P_AFFTY'.
CLEAR p_affil.
CLEAR p_affty.
MODIFY SCREEN.

ENDIF.
ENDLOOP.
ENDIF.
IF NOT cb_adw IS INITIAL.
p_affil = gc_adw.
p_affty = gc_a.
MODIFY SCREEN.
ENDIF.

please guide...