Setting classpath to include junit

Hi, I couldnt find a java-help mailing list like there is for
gcc-help, so I hope this is the right place to post. Im trying to use
gcj from the command line to compile a java assignment for university,
but i cant seem to work out how to add junit to my build path (is that
a java-y term, idk). Anyway, I can compile using gcj as long as I dont
go outside the scope of libgcj.jar. Im using a debian system, and I
have a directory called /usr/share/java/ which contains junit.jar. Ive
tried virtually every permutation of CLASSPATH, with things like
export CLASSPATH=/usr/share/java/junit.jar
and so on. Anyway, regardless of what i do i keep getting a
LinkedDequeTest.java:3: error: The import org.junit cannot be resolved
        import org.junit.Test;
I gave in and installed the sun javac, only to get a similar error message.
LinkedDequeTest.java:3: package org.junit does not exist
import org.junit.Test;
So im hoping that its just a problem with my configuration. Ive
already purged sun java and vrms is slightly less mad at me. Thanks
for any help, I just cant seem to figure this one out on my own.

-- 
Carl