Unable to specify Channel,No such device or address

Dear Friends!
I am new to asterisk.So dont mind for my silly questions

I have downloaded the 1.2.0 versions of all ( asterisk,Asterisk Addones,Asteris Sound,Libpri and Zaptel).I am able to install successfully.When I modify the Zapata.conf file with my desired channel it is not working.I mean to say that it is showing an warning that Unable to Specify Channel,No such device or driver.Followed by unable to open channel 1.
I think that is showing an error code of 6847.But I am not sure that is the error code or not.

I am giving you my Zapata.conf file as follows

trunckgroup]
; define trunck group
[channels]
; hardware channels definition
echocancel = yes
echocancelwhenbridged=yes
echotraining=yes
hidecallerid=no
threewaycalling=yes
transfer=yes
callwaiting=no

language = en
signalling = fxo_ks ;Use FXO signalling for an FXS channel
group=1
context=outgoing
channel =>1 ;telephone attached to port 1

signalling=fxs_ks ;Use FXS signalling for as FXO channel
callerid=asreceived
group=2
context=incoming
channel=>4 ; telephone line attached to port 4

Here is my zaptel.conf file.

fxoks = 1
fxsks = 4
loadzone = in
defaultzone = in

I am trying to run it by using 1.modprobe zaptel followed by modeprobe wctdm and after that asterisk -vvvvvvc.

When I compiled the modprobe wctdm the gree led at my digiun card glows. I think the connection is OK since I have connected the card in the corresponding channels which are glowing.

I am also available at “shiva_pd1983”, Its my IM Id at yahoo.I need a help regarding my query.I have already spent 20 days in this .

Waiting for a quick response.
Thanks in Advance
Shiva