Locked up? Reboot!

If your iPhone locks up or stops working for any reason other than a low battery, you’ll need to reboot it. This is analogous to turning your desktop or laptop computer off and on again, and it clears up a lot of problems. Press and hold down the Sleep/Wake button on the top edge of the device and the Home button until the Apple logo appears on the screen. Then release both buttons and wait until the Home screen appears.