[LBo] Installing Postfix - halted

[Kojo Nyame]

I have been trying to install postfix on Kubuntu 7.04. I am following the
tutorial at (
http://www.howtoforge.com/virtual_postfix_mysql_quota_courier_ubuntu_edgy )
but after following several commands which went well I reached the command
below which also went well:

apt-get install build-essential dpkg-dev fakeroot debhelper libgdbm-dev
libldap2-dev libpcre3-dev libssl-dev libsasl2-dev postgresql-dev po-debconf
dpatch libdb4.3-dev libmysqlclient15-dev

Following the this command I got an error from executing the next commands:

cd /usr/src
apt-get source postfix

The error I get is : sh: dpkg-source: not found
                          unpack command 'dpkg-source -x postfix_2.3.8-2.dsc'
failed
                           check if the 'dpkg-dev' package is installed.
                           child process failed.

I am still a novice and I know this may be simple but I am not sure how to
proceed.

-- 
HETEP

Kojo

"Faith is nothing but a living, wide-awake consciousness of God within."
— Gandhi