chan_sip.c:13859 handle_request_invite: Extension not found

Hi,

I installed asterisk on Linux Red-Hat AS 5.1
I read the Asterisk documents and then tried to connect first time two X-Lite soft phones through the Asterisk box using sip without success

I get the following error when I am trying to call

chan_sip.c:13859 handle_request_invite: Call from ‘gili’ to extension ‘nir’ rejected because extension not found

sip.conf

[general]
context=default
bindport=5060
bindaddr=0.0.0.0
srvlookup=yes

[gili]
type=friend
regexten=gili
host=dynamic
secret=SSE
disallow=all
allow=ulaw
allow=alaw
bindport=5060
bindaddr=0.0.0.0
srvlookup=yes
callerid=gili

[nir]
type=friend
regexten=nir
host=dynamic
secret=SSE
disallow=all
allow=ulaw
allow=alaw
bindport=5060
bindaddr=0.0.0.0
srvlookup=yes
callerid=gili

extensions.conf

[globals]

[general]
autofallthrough=yes

[incoming_calls]

[internal]
exten => gili,1,Verbose(1|Extension gili)
exten => gili,n,Dial(SIP/gili,30)
exten => gili,n,Hangup()
exten => nir,1,Verbose(1|Extension nir)
exten => nir,n,Dial(SIP/nir,30)
exten => nir,n,Hangup()

[phones]
include => internal

The two X-lite shoft phone and the asterisk box are in the same subnet (private IP)

Can someone help me with this one?

Thanks in advanced