ya, for the good place to get the unlock code for your Samsung model mobile, just visit this site Super Unlock Codes , it provides the step by step instructions and easy methods for unlocking your mobile from the network lock........at the same time to get the unlock code you have to give some information about the mobile to this site that is your IMEI number,network & country lock after that within a short period you can get the code ............
If you unlock your phone using the unlock code then your phone gets permanently unlocked....After that, you can use it with any other network's sim card...........