Installing Linux-software (Mozilla 1.5)

[a at jenisch.at]

Hi,

Being relatively new to FreeBSD I tried to install the Linux-version
of Mozilla 1.5 (mozilla-i686-pc-linux-gnu-1.5-sea.tar.gz). After
untarring and starting mozilla-installer I end up with

bash-2.05b# ./mozilla-installer
./mozilla-installer-bin: error while loading shared libraries: libgtk-1.2.so.0: cannot open shared object file: No such file or directory
bash-2.05b# 

Any ideas where I can get hold of the required library? I've already done a 

make search name=libgtk in /usr/ports but to no extent...

Thanks much in advance for any clue,
-ewald