Finding and killing an Oracle session...

Finding a session:
------------------
SELECT USERNAME, OSUSER, MACHINE, SID, SERIAL#, STATUS, SECONDS_IN_WAIT
from v$session
WHERE
TYPE != 'BACKGROUND'
AND username = 'STAN4'
order by seconds_in_wait desc

Killing a session:
------------------
ALTER SYSTEM KILL SESSION 'sid,serial#' IMMEDIATE;