iPhone will not detect my fingers.

Hi.
Yesterday, my iphone was working perfectly fine. I charged it over night on my desk and this morning, when I tried to unlock my iphone, it would not detect my fingers. I was not able to use the slider at all. So, I tried to turn it off and nothing works at all. It is still on the same page of turning it off. I have never dropped it and i only recently got it. Why would it not detect my fingers??