How to check if my 5s is really unlocked?

[Onamuji]

graylocks wrote:
[quote=Microman]
I restored two ATT iphone 5s last week, and everytime you do a restore to factory I got the CONGRATS YOUR UNLOCKED message

it occurs to me to ask-where does the message appear? on the phone screen or the computer (iTunes) screen? I've been expecting to see it on the computer so maybe I missed it.
A window in iTunes says something like, "Congratulation's, your iPhone has been unlocked."

But any other messages will knock it off the screen, so it may not persist long enough for you to see the message.