Hi, I need a little help here please......

I am trying to compile the latest version of Firefox. But when I configure it I get the following error:-

checking for LC_MESSAGES... yes
checking for gtk-config... no
checking for GTK - version >= 1.2.0... no
*** The gtk-config script installed by GTK could not be found.
*** If GTK was installed in PREFIX, make sure PREFIX/bin is in
*** your path, or set the GTK_CONFIG environment variable to the
*** full path to gtk-config.
*** GTK+ is available from ftp://ftp.gtk.org/pub/gtk
configure: error: Test for GTK failed.

I have looked at where the files should be according to the program file list of gtk, which is /etc/opt/gnome/gtk. I have exported the path using export PATH=$PATH:/etc/opt/gnome/gtk.......

But it still throws up an error. Am I looking in the wrong place? If so, how do I search for the file? I presume it's looking for gtk.conf

Regards