Samsung SGH-C225NBATMB - Manual (Page 17)

Display
17
Backlight
The display is illuminated by a backlight. When you press any
key, the backlight illuminates. It turns off if no key is pressed
within a given period of time, depending on the Back Light
menu option.
To specify the length of time for which the backlight is active,
set the Back Light menu option (Menu 5.1.5); see page 81
for further details.
Main Screen Display
Your phone has a main screen display. It indicates that you
have an incoming call or a message, and notifies you at the
specified time when you set an alarm.