Motorola C390 - Manual (Page 60)

60 - Calling Features
Using Call Waiting
When you are on a call, an alert tone sounds to indicate
that you have received another call.
You must turn on call waiting to use the feature. To turn call waiting
on or off:
Putting a Call On Hold
Press To
1 N answer the new call
2 SWITCH ( +)
or
switch between calls
LINK ( -)
or
connect the 2 calls
M >
End Call On Hold end the call on hold
Find the Feature M > Settings > In-Call Setup
> Call Waiting
Press To
HOLD ( +) (if available)
or
M > Hold
put the call on hold