LG LS860 - Manual (Page 9)

9
Getting to know your phone
7. When the screen freezes
If the screen freezes or the phone does not respond when you try to
operate it:
Remove the battery, reinsert it, then turn the phone on.
OR
Press and hold the Power/Lock Key for 10 seconds to turn it off.
If it still does not work, please contact the service center.