My iphone 5 screen is unresponsive?

Ny iphone 5 screen is being unresponsive. It was fine like hours ago all of suddenly it doesn't let me to unlock my phone. I'm trying to slide to unlock but I can't. Can anybody help me find a solution?!

Added (1). I've never synced to my iTunes it's telling me I need to unlocked with the pass code but I can't since the screen is not working. How do I reset it when I can't go in.

Try doing a hard reset

To hard reset hold the power button and the home button until the screen goes black