LG LG855 - Manual (Page 9)

To answer a call:
+ Touch and drag to the right.
If you were already on a call, the first call is placed
on hold while you answer the new call. To silence
the ringer of an incoming call, press the down
Volume Key.
Your phone notifies you of incoming calls in the
following ways:
+ The phone rings or vibrates.
+ The backlight illuminates.
+ The screen displays an incoming call message.
To decline a call and divert it to voicemail:
+ Touch and drag
to the left.
The caller is sent directly to your voicemail box to
leave a message.