Programmer - How can I get Hudson to be able to access JUnit?

Programmer Question

I've got Hudson running on TOMCAT, it can build my Netbeans project using the ant build.xml, but it won't run any of my unit tests because of what I assume is a problem with the classpath:

package org.junit does not exist
    [javac] import org.junit.After;
    [javac]                 ^

But I've got the junit-4.8.1.jar on the classpath in /etc/environment and I can successfuly run the junit tests from a console using

java org.junit.runner.JUnitCore org.junit.tests.AllTests

My CLASSPATH is set to /home/bedwyr/junit4.8.1/junit-4.8.1.jar:.

Am I going wrong somewhere or is there anything else I need to set?