1-power on WITHOUT sim card
2-push in your sim card without removing battery
3- type : *2767*2878#
your phone should restart after 1 min
5- now type : *746 56 25*638*0000 0000*0000 0000#
6- now type :#746 56 25*638*0000 0000#
your UNLOCK CODE is 0000 0000 now & all codes deactivated
THIS WORKED FOR ME ON MY SAMSUNG JET S8000, BUT I'M NOT SURE WHETHER IT WORKS FOR OTHER SAMSUNG PHONES