disable and turn off ipv6 in ubuntu linux

i am doing this on ubuntu linux 10.*

you must of course sudo or be root before proceeding

edit /etc/sysctl.conf

add the following lines to the bottom of the file:
#disable ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

now reboot, or reinitialize sysctl by issuing this command:
sysctl -p