How can I get Prefix application?

***I use the asterisk-1.4.13

This is error messages for me
—>
[Oct 27 21:10:10] WARNING[26786]: pbx.c:1797 pbx_extension_helper: No application ‘Prefix’ for extension (internal, 0935543871, 4)

This is extensions.conf for me
----->
[cisco]

exten => _X.,1,Answer()
exten => _X.,2,SendText(The current extension is: ${EXTEN:1})
exten => _X.,3,Wait(5)
exten => _X.,4,Prefix(400002886)
exten => _400002886X.,5,SendText(The new extension number is: ${EXTEN})
exten => _400002886X.,6,Dial(SIP/${EXTEN}@${CISCOADDRESS},30,Ttm)
exten => _400002886X.,7,Hangup()

***Somone can help me to solve the problem?
Thank you so much!

Hi

Prefix was removed at about 1.2.6 or so.

What are you trying to acheive ?

Ian

Hi,Ian

I’m trying to do that it can attach the number in front of the called ID.
For example,the called ID is 935543871,then I want to attach 400002886
in front of it.So the called ID is become to 400002886935543871.How should
I do?

Thanks a lot
Bryant