to unlock ur samsung e720. put in the sim card you want to use, when it comes up sayin wrong card type in *#9998*3323# the last 4 digits typed will show up as lines. it will then tell u to press exit, do so. then press 7. dont press anything and ur fone will restart on the network u wanted. only problem with is u have to do it everytime u take ur sim out but it works.
