apt-get install firefox
E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied)
E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?
smiley@smileybox:~$ sudo apt-get install firefox
E: dpkg was interrupted, you must manually run 'sudo dpkg --configure -a' to correct the problem.
smiley@smileybox:~$ sudo dpkg -- configure -a
dpkg: error: need an action option

Type dpkg --help for help about installing and deinstalling packages [*];
Use 'apt' or 'aptitude' for user-friendly package management;
Type dpkg -Dhelp for a list of dpkg debug flag values;
Type dpkg --force-help for a list of forcing options;
Type dpkg-deb --help for help about manipulating *.deb files;

Options marked [*] produce a lot of output - pipe it through 'less' or 'more' !