If you want to add debian repository
Open /etc/apt/sources.list as root and add these lines
## Debian Stable (etch)
deb http://ftp.it.debian.org/debian/ stable main contrib non-free #deb-src http://ftp.it.debian.org/debian/ stable main contrib non-free ## Security updates
deb http://security.debian.org/ stable/updates main contrib #deb-src http://security.debian.org/ stable/updates main contrib
