Funtion Module for user exits variables in BEx Queries.

Question

Hi,
This is for BW Query customer exit variable (zvar2) for include ZXRSRU01 and exit :EXIT_SAPLRRS0_001.
Can anyone please suggest the function modules that can be used to do the following.
1)Read value of zvar1 from selection screen whatever 
  user enters at run time.
2)How to define the zvar2 in the include. zvar2 is the 
  variable created in BEx to be populated from this
  customer exit.
3)How to use case statment where once the value for zvar1
  is determined then,
   Case zvar1.
   when zvar1 = 0 , then zvar2 = 10
   when zvar1 = 1 , then zvar2 = 20
3) Assign zvar2 value as computed in the case statement.
Can anyone please help with the code to achieve this.
Any information regarding function modules that can help write user exits for variable reading and input will be greatly helpful.
Thanks
Sarah.

Answer 1

Hi Sarah,
You don't need any FM for your issue.
Please try thie sample code :
DATA: VAR_INPIUT LIKE RRRANGEEXIT.
CASE I_VNAM.
  WHEN 'ZVAR2'.
   CLEAR L_S_RANGE.
   IF I_STEP = 2."PROCESSED AFTER VARIABLE INPUT
*Reading value of ZVAR1
    LOOP AT I_T_VAR_RANGE INTO VAR_INPIUT
      WHERE VNAM = 'ZVAR1'.
      CASE VAR_INPIUT-LOW.
*FILLING ZVAR2
       WHEN 0.
          L_S_RANGE-LOW     = 10.
       WHEN 1.
          L_S_RANGE-LOW     = 20.
      ENDCASE.
      L_S_RANGE-SIGN     = 'I'.
      L_S_RANGE-OPT      = 'EQ'.
      APPEND L_S_RANGE TO E_T_RANGE.
      EXIT.
    ENDLOOP.
  ENDIF.
ENDCASE.
Hope this helps
Joe