Problem while Creating Validation user exit in GGB0

Dear All ,

i have created one Validation user-exit  in GGB0 for FI followed all steps  1

1)  Copied RGGBR000 to ZRGGBR000  .

2)  added exit-name  , title ,parameter none  .

  exits-name  = 'ZORD'.
  exits-param = c_exit_param_none.        "Complete data used in exit.
  exits-title = text-105.                "Posting date check
  APPEND exits.

3)  also  form . endform 

  FORM zord USING b_result.
tables : coas .
if sy-tcode ='MB1A' .


endif.


ENDFORM. 

4) done changes  in table t80d  using GCX2

modified zprogram name  for application area gblr

5)  there is also entry  in ob28 for validation rule 

6) executed report  RGUGBR00  .

7) when i go in GGB0  and put cursor  on exit  and click on ABAP editor  it show that code  ...

8) when i called that exit  through GGB0 it does not gives call to that exit NAME "ZORD" ?

Could you please guide us for the same  .

I have attached the screen shot of exit created  by name zord  .

Regards

Deepak.