Make apt-get and aptitude work through a proxy

1) sudo vi /etc/apt/apt.conf.d/70debconf
2) It should already have: DPkg::Pre-Install-Pkgs {"/usr/sbin/dpkg-preconfigure --apt || true";};
3) Add this after what's there (no blank lines):
Acquire {
        http {
                Proxy "http://user:pass@host:port";
                No-Cache "false";
                Max-Age "86400";
                No-Store "false";
        };
};
Thanks