iphone when black can't see anything

[671iphone]

My iphone just went black. I was using it all day and after my last call, without knowing, my sisterinlaw asked for my phone and then told me that it wasn't working. i can recieve calls, just can't see who it is, but i can't answer it. When i plug it to the usb it charges but i still can't see anything. Can someone please help me?

[iNinja]

Soft rest. Hold down the home and power buttons for about 10 seconds. You should see the screen flash and the white apple logo appear. Then let go of the buttons. Your phone should reboot fine. If it doesnt, try a full restore in Itunes, if that doesnt work, you need a genius ;)

[FlwrPwer]

My iphone just went black. I was using it all day and after my last call, without knowing, my sisterinlaw asked for my phone and then told me that it wasn't working. i can recieve calls, just can't see who it is, but i can't answer it. When i plug it to the usb it charges but i still can't see anything. Can someone please help me?

I would try a restore. If that doesn't work, I'd say take it back to the apple store.