how to resolve the bdc call transaction in ALV report

Dear Experts, i am executing the alv report program and in alv report program one bdc is there..

after executing output is showing in alv format but one button is there (update master)..when i am clicking update button the bdc is run but is not updated in the material master..

after executing my bdc is not updated in mm02..how to resove it?

CALL TRANSACTION 'MM02' USING BDCDATA MODE MODE

                                                          UPDATE 'S'

                                                  MESSAGES INTO MESSTAB.

how to resolve it