How To Lock - Nokia Lumia 720
Learn how to lock on your Nokia Lumia 720.Want to avoid accidentally making a call when your phone is in your pocket or bag?
Press the power key.
Unlock the keys and screen
Press the power key, and drag the lock screen up.
Set the keys and screen to lock automatically
On the start screen, swipe left, tap Settings > lock screen > Screen times out after, and select the length of time after which the keys and screen are locked automatically.