Error in the ABAP Code for Customer Exit Variable

Question

Could you please update me what is the wrong with the below ABAP Code developed for Customer Exit Variable in BW
i created a Variable (ZVWKNO) of Customer Exit,Single Value ,Mandatory and Variable is ready for input
In CMOD i had written the below Code:
When 'ZVWKNO'.
DATA: WEEK(2) TYPE N,
WEEKNO(2) TYPE N.
IF i_step = 1.
l_st_date = SY-DATUM.
CALL FUNCTION 'DATE_GET_WEEK'
EXPORTING
DATE = l_st_date
IMPORTING
WEEK = l_fn_week.
CHECK sy-subrc = 0.
WEEK = l_fn_week+4(2).
If WEEK 0.
WEEKNO = WEEK - 1.
l_s_range-low = WEEKNO.
l_s_range-sign = k_sign_inclusive.
l_s_range-opt = k_option_equals.
APPEND l_s_range to e_t_range.
ENDIF.
ENDIF.
But when i execute the query the default value is not populated with Week-1 No in the variable screen
Please update me what went wrong
Thanks

Answer 1

Case ZVWKNO.                "write this with out comments
When '1'.              "write the value that needs to equal with value in varaible ZVWKNO after when in sungle quotes
DATA: WEEK(2) TYPE N,
WEEKNO(2) TYPE N.
IF i_step = 1.
l_st_date = SY-DATUM.
CALL FUNCTION 'DATE_GET_WEEK'
EXPORTING
DATE = l_st_date
IMPORTING
WEEK = l_fn_week.
CHECK sy-subrc = 0.
WEEK = l_fn_week+4(2).
If WEEK 0.                                    "check this Week Minimum is '01' and Maximum '52'
WEEKNO = WEEK - 1.
l_s_range-low = WEEKNO.
l_s_range-sign = k_sign_inclusive.
l_s_range-opt = k_option_equals.
APPEND l_s_range to e_t_range.
ENDIF.
ENDIF.
Prabhudas