Custom Extensions

Hi! I’m very new to Asterisk. I’m just learning it. I have asterisk and FreePBX installed. I want to learn how to create custom extensions. I want the system to answer a call (on number 1114), say my number and then i want it to dial another number (say 1111).
I have written these lines in extension_override_freepbx.conf:

[from-internal-additional]
exten => 1114,1,Answer()
exten => 1114,n,Playback(cdir-welcome)
exten => 1114,n,SayDigits(${CALLERID(number)})
exten => 1114,n,Dial(SIP/1111)
exten => 1114,n,Hangup()

So, it answers, plays “welcome”, says my number but doesn’t dial number 1111

Then i write:
exten => 1114,n,WaitExten()

Now, if i dial 1114, listen to the voice and then enter 1111 - this works. But I want this: exten => 1114,n,Dial(SIP/1111)
Please tell me what am i doing wrong? Why this line exten => 1114,n,Dial(SIP/1111) doesn’t work?
p.s. sorry for my english

Here is the output of CLI when I’m dialing 1114:

== Using SIP RTP TOS bits 184
== Using SIP RTP CoS mark 5
– Executing [[email protected]:1] Answer(“SIP/1112-00000001”, “”) in new stack
– Executing [[email protected]:2] Playback(“SIP/1112-00000001”, “cdir-welcome”) in new stack
– <SIP/1112-00000001> Playing ‘cdir-welcome.slin’ (language ‘en’)
– Executing [[email protected]:3] SayDigits(“SIP/1112-00000001”, “1114”) in new stack
– <SIP/1112-00000001> Playing ‘digits/1.gsm’ (language ‘en’)
– <SIP/1112-00000001> Playing ‘digits/1.gsm’ (language ‘en’)
– <SIP/1112-00000001> Playing ‘digits/1.gsm’ (language ‘en’)
– <SIP/1112-00000001> Playing ‘digits/4.gsm’ (language ‘en’)
– Executing [[email protected]:4] SayDigits(“SIP/1112-00000001”, “1112”) in new stack
– <SIP/1112-00000001> Playing ‘digits/1.gsm’ (language ‘en’)
– <SIP/1112-00000001> Playing ‘digits/1.gsm’ (language ‘en’)
– <SIP/1112-00000001> Playing ‘digits/1.gsm’ (language ‘en’)
– <SIP/1112-00000001> Playing ‘digits/2.gsm’ (language ‘en’)
– Executing [[email protected]:5] Dial(“SIP/1112-00000001”, “SIP/1111”) in new stack
[2012-04-19 15:40:57] WARNING[7713]: app_dial.c:2218 dial_exec_full: Unable to create channel of type ‘SIP’ (cause 20 - Unknown)
== Everyone is busy/congested at this time (1:0/0/1)
– Executing [[email protected]:6] Hangup(“SIP/1112-00000001”, “”) in new stack
== Spawn extension (from-internal, 1114, 6) exited non-zero on ‘SIP/1112-00000001’
– Executing [[email protected]:1] Hangup(“SIP/1112-00000001”, “”) in new stack
== Spawn extension (from-internal, h, 1) exited non-zero on ‘SIP/1112-00000001’

What is SIP111? If it is a trunk it is refusing the call:

2012-04-19 15:40:57] WARNING[7713]: app_dial.c:2218 dial_exec_full: Unable to create channel of type ‘SIP’ (cause 20 - Unknown)