the unix equivalent of SET (in Windows) is ENV

or, you could look under /oracle (or where ever you installed JRE), you will see a dir. for JRE/ and below that a dir. (that will be the version #)

This is what I see on my system:

/oracle/jre>ls -lrt
total 16
drwxrwxr-x 5 oracle dba 8192 Jun 3 2002 1.3.1
drwxrwxr-x 4 oracle dba 8192 Nov 22 2002 1.1.8