BADI ME_PROCESS_PO_CUST~CHECK get not fire

I HAVE INSERTED code in badi method ME_PROCESS_PO_CUST -- CHECK

and i will get up to break-point which i have puted in this method while saving PO using me22n but message is not displaying.

code:

*MESSAGE I001(ZDP) WITH 'HI'.

*IF SY-UNAME = 'DEV1'.

*MESSAGE I001(ZDP) WITH 'HI'.

*ENDIF.

what else precaution to take?

regards,

dushyant.