My exit in validation exit dont execute for fb02

Question

Hi guys,
Validation in field BSEG-ZLPRS for FB02 transaction.
1.- i add new form in se38 -> ZGGBR000
FORM u105 CHANGING b_result.
  BREAK-POINT.
  DATA: znolib  LIKE zliber-znolib.
  SELECT SINGLE znolib
    INTO znolib
    FROM zliber
    WHERE bukrs = bseg-bukrs AND
          username = sy-uname.
  IF sy-subrc <> 0.
    b_result = b_false.
    MESSAGE i031(z001) WITH sy-uname.
  ELSE.
    IF znolib = 'N'.
      b_result = b_false.
      MESSAGE i031(z001) WITH sy-uname.
    ELSE.
      b_result = b_true.
    ENDIF.
  ENDIF.
ENDFORM.
2.- After activated i use RGUGBR00 for rebuilding validation structures
3.- The condition is SYST-TCODE = 'FB02', cause there is no specific condition, we need to check thhis field for all circunstances
I have all ok in ggb0
Best regards
Jua

Answer 1

Not solved yet...
in table GB01 i have:
BOOLCLASS = 9
CLASSTYPE = B
BLCTAB = BSEG
BCLFIELD = *
BEXCLUDE = ' '
Since i am not sustituying the field only validating its not necessary to change....
But my exit still not working
Best regards
Juan