hang on, if you're trying to install the plugin you need to create soft links from your mozilla plugins directory to the actual plugin. To do this, change to your mozilla plugins dir, and do (something like, depending on your path and the version of the plugin you want to install):
ln -s /usr/java/j2re1.4.2_04/plugin/i386/ns610/libjavaplugin_oji.so
To check if it was successful, restart mozilla and type 'about

lugin' in the address bar