I was trying to install postfix on Ubuntu 11.10 for SMTP support... I typed
sudo apt-get install postfix
and then the installation started.
But during installation a configuration screen popped up which requested me to select an option. Now the problem is that there is no link to accept an option in the configuration screen, and as I can't select an option the installation process stalls.
If i exit the terminal and again try to re-install i get a message
could not get lock /var/cache/apt/archives/lock -open(11. resource temporarily unavailable)
Screenshots of the problem: