a) Press when call is in progress,
increase or decrease the volume, when
the phone is ringing, silences the
ringer. On the home screen when no
call in progress, increase or decrease
the ringtone volume or sets the phone
to the silent instead of ringing. In other
applications, controls the volume of
music, spoken directions and other
audio.
b) Press and hold to quickly increasing
ringtone volume to maximum or
minimum.
