Apt-get :: Updating the Firefox Browser - not extensions

Hi! I am aware of some firefox vulnerabilities lately, and I would like to know how can I update firefox to the latest version? I know that the DSL version was customized for version 1.2 of GTK+.

I downloaded the latest firefox version from http://mozilla.org/firefox. When i tried to install it (a shell script comes with it), but it reported that i did not have libgtk2 installed.

I tried to use apt-get to get firefox and libgtk2. I tried way too many apt-get install(s), and got the following error

"E: Couldn't find package NAMEOFPACKAGE."

Well, after researching online, i found out that the package for gtk2 is libgtk2.0-0. I tried it and got 2 errors:

"The following packages have unmet dependencies:
 libgtk2.0-0: Depends: libgtk-common but it is not going to be installed
                  Depends: libpango1.0-0 (>=1.0.1) but it is not going to be installed.
E: Broken packages"

If i need this to get the latest version of firefox, how can i maintain my system secure and up to date? I would appreciate any help with this matter.

Thank you.