I have an at&t HTC one X that was supposed to be unlocked when I got it and when I put in my non at&t sim the sim unlock screen doesn't come up which leads me to belive it is. The problem is when I search for available networks the only thing that shows up is at&t and US which leads me to believe it's not unlocked. How can I unlock it if the screen to enter the unlock code doesn't come up when I put my sim in? Is there another way such as a code to punch in on the dialpad that would bring this screen up? Any help with this issue would be greatly appreciated