Help in transformation routine

Question

I have to put an indicator for delivery block in transformation routine.
Logic: if headed delivery block 'LIFSK' is not blank, result is 'X'.
Here is my code which is not working:
IF SOURCE_FIELDS-LIFSK NE ''.
      RESULT = 'X'.
    ENDIF.
But this code is not doing anything. I tired using 'test' function in transformation, it gives abap dump.
What is the problem. Code is in right place in transformation routine.
A similar code for item level block is working:
More details:
$$ begin of routine - insert your code only below this line        -
    ... "insert your code here
*--  fill table "MONITOR" with values of structure "MONITOR_REC"
*-   to make monitor entries
    ... "to cancel the update process
   raise exception type CX_RSROUT_ABORT.
    ... "to skip a record
   raise exception type CX_RSROUT_SKIP_RECORD.
    ... "to clear target fields
   raise exception type CX_RSROUT_SKIP_VAL.
    IF SOURCE_FIELDS-ZZ_LIFSP ne ''.
      RESULT = 'X'.
    endif.
$$ end of routine - insert your code only before this line         -
  ENDMETHOD.                    "compute_ZDELIBLK
Thanks
Jeff
Edited by: Jeff Edwards on Aug 17, 2008 10:34 PM

Answer 1

No luck.
Error analysis
    The following checkpoint group was used: "No checkpoint group specified"
    If in the ASSERT statement the addition FIELDS was used, you can find
    the content of the first 8 specified fields in the following overview:
    " (not used) "
    " (not used) "
    " (not used) "
    " (not used) "
    " (not used) "
    " (not used) "
    " (not used) "
    " (not used) "
ST22 / ABAP Editor :
*-- Get field name from source field with extern posit.
  READ TABLE i_t_seg_source ASSIGNING <ls_s_seg_source>
    WITH KEY segid = i_segid.
  ASSERT sy-subrc = 0.
  IF sy-subrc = 0.
    READ TABLE <ls_s_seg_source>-t_field ASSIGNING <ls_s_field>
      WITH KEY position = l_posit_source_ex.
> ASSERT sy-subrc = 0.
  ENDIF.
*--  r_s_parameter-param_id has to be set out side due to type inheritance of RuleStepMapping
  CONCATENATE '<' <ls_s_seg>-y__nm '>' INTO
  c_s_connector-s__nm.
  c_s_connector-f__nm = <ls_s_field>-fieldname.
ENDMETHOD.