unlockin my samsung

[wendirooney]

i have a samsung and sprint gave me my code to unlock it, but it keeps saying my sim card is invalid, and nothing pops up to tell me where to put my code

 

[Saga Lout]

MERGED QUESTION
Question from wendirooney : "ive done all that and it says my sim card is invalid"

ive taken all the steps to unlock my phone, but it keeps saying my sim card is invalid