[Asterisk-Users] All-Page in Asterisk

[willy at yponeinc.com]

Hi ..
When the receptionist parks a call for someone who is in the
building 
but not at their desk, she does an 'allpage' which
blares-out over
the intercom system: 'Willy you have a call parked at 101'.
Willy can then just grab any phone (kitchen, hall, computer
room) 
and pick up the parked call.  How do we do an 'allpage' in
asterisk?