Newbie question on dselect

[Rick.Tan@Eng.Sun.COM (Rick Tan)]

Hello,

I just successfully installed slink 2.1 on a sparc machine.  When I attempted
to use "dselect" to install some other packages off the net, I ran into the
following problem.

Get http://http.us.debian.org stable/contrib Packages
Get http://http.non-us.debian.org stable/non-US Packages
Error http://http.us.debian.org stable/contrib Packages
 Couldn't lookup host http.us.debian.org
Error http://http.non-us.debian.org stable/non-US Packages
 Couldn't lookup host http.non-us.debian.org 
 .
 .
 .
update available list script returned error exit status 1
Press RETURN to continue.

I believe the errors in the above has to do with the fact that the machine
is behind a firewall.  How do set the proxy server information in the
system.  What program or tool is available for this?

Thanks in advance.

-Rick