change log for Z table

Hi all,

The change log is not working.The log is not correct.

My setting:

1 set rec/client = ALL RZ10 and restart system

2 create Z table and set log data changes in technical setting

3, set change document for data element

4 SCDO, create object and add Z table

5 SCDO, generate update program

6 in program,call the function

DATA: LT_CDTXT LIKE TABLE OF CDTXT,

       LW_CDTXT LIKE CDTXT,

       LV_OBJID TYPE CDHDR-OBJECTID.

LV_OBJID = ZSHTH-HTNO_D.

LW_CDTXT-UPDKZ = 'U'.

LW_CDTXT-TEILOBJID = ZSHTH-HTNO_D.

APPEND LW_CDTXT TO LT_CDTXT.

DATA: LT_XHTFK LIKE TABLE OF YZMMT_HTFK,

       LW_HTFK LIKE YZMMT_HTFK,

       LT_YHTFK LIKE TABLE OF YZMMT_HTFK.

LOOP AT GT_ITEM_O INTO LW_ITEM_O.

   MOVE-CORRESPONDING LW_ITEM_O TO LW_HTFK.

   LW_HTFK-KZ = 'U'.

   APPEND LW_HTFK TO LT_YHTFK.

   ENDLOOP.

LOOP AT LT_ITEM_MOD INTO lw_item.

   MOVE-CORRESPONDING lw_item TO LW_HTFK.

   LW_HTFK-KZ = 'U'.

   APPEND LW_HTFK TO LT_XHTFK.

   ENDLOOP.

(YHTFK IS NOT EQ XHTFK)

CALL FUNCTION 'ZHT_WRITE_DOCUMENT'

       EXPORTING

         objectid                      = LV_OBJID

         tcode                         = SY-TCODE

         utime                         = SY-UZEIT

         udate                         = SY-DATUM

         username                      = SY-UNAME

*       PLANNED_CHANGE_NUMBER         = ' '

        OBJECT_CHANGE_INDICATOR       = 'U'

*       PLANNED_OR_REAL_CHANGES       = ' '

*       NO_CHANGE_POINTERS            = ' '

        UPD_ICDTXT_ZHT                = 'U'

*       UPD_ZMMT_HTFK                 = 'X'

       TABLES

         icdtxt_zht                    = LT_CDTXT

         xzmmt_htfk                    = LT_XHTFK

         yzmmt_htfk                    = LT_YHTFK

               .

     COMMIT WORK.

7 check table CDPOS

the field new value and old value are empty.And field name is empty too.

Thanks

Kical