Turn your device on and off and perform a soft reset.
INSTRUCTIONS & INFO
To turn iPhone on, press and hold the Sleep/Wake button until the Apple logo appears.
To turn iPhone off, press and hold the Sleep/Wake button until the red slider appears, then drag the slider.
To unlock iPhone, press either the Sleep/Wake or Home button, then press the Home button again. To lock iPhone, press the Sleep/Wake button. Note: iPhone locks automatically if you don't touch the screen for a minute or so. To adjust the timing, go to Settings > General > Auto-Lock. To set a passcode lock go to Settings > Passcode.
If your device stops responding, you can reset it by pressing and holding both the Sleep/Wake and Home buttons for at least ten seconds, until the Apple logo appears. Note: If your device remains unresponsive or does not turn on click here to learn what to do.