something, sorry, I couldn't resist.
I don't know much about scripting, but couldn't you do this somewhere at the beginning of the file
Code:
CLASSPATH=/downloads/apache-tomcat-5.5.17/common/lib/servlet-api.jar
JAVA_HOME=/downloads/j2sdk1.4.2_13/
This is what I usually do to assign a variable in a script. I may be horribly wrong though.