Logic need for my selection screen

Question

Hi,
i designed my selection screen
PARAMETERS:
  rb_alv   RADIOBUTTON GROUP g2,                                                        " Radio 1
  rb_pc    RADIOBUTTON GROUP g2,                                                        " Radio 2
  rb_unix  RADIOBUTTON GROUP g2.                                                        " Radio 3
*File path
PARAMETERS: pa_ftxt TYPE rlgrap-filename.
Below isMy requirement is :How to do it???please help
Do not hard-code the directory output for Unix. Just make sure the selection logic checks to make sure a value exists in the path field if either download option (pc/unix) is set). For the PC default, use u2018c:\temp\veninfo.txtu2019 as a constant.
Thanks
asis

Answer 1

PARAMETERS:
rb_alv RADIOBUTTON GROUP g2 user-command 'RAD', " Radio 1
rb_pc RADIOBUTTON GROUP g2, " Radio 2
rb_unix RADIOBUTTON GROUP g2. " Radio 3
*File path
PARAMETERS: pa_ftxt TYPE rlgrap-filename.
at selection-screen output.
if rb_pc = 'X'.
pa_ftxt = 'c:\temp\veninfo.txt'.
else.
clear pa_ftxt.
endif.
at selection-screen on value request for pa_ftxt.
CALL FUNCTION 'F4_DXFILENAME_TOPRECURSION'
EXPORTING
i_location_flag = 'A'
i_server = ' '
i_path = ' ' "here you can give the path of the server directory
IMPORTING
o_path = l_path
abend_flag = l_abend_flag
EXCEPTIONS
communication_failure = 1
system_failure = 2
rfc_error = 3.
IF sy-subrc EQ 0.
p_file = l_path.        "This gives you the path
ENDIF.
IF l_abend_flag = 'X'.
EXIT.
else.
Move l_path to your screen field pa_ftxt.
ENDIF.