The connection bewteen v$lock and v$sql

[xiongye]

I want to find the sql cause lock,I use the sql
SELECT object_name,SESSION_ID,SERIAL#,machine,
osuser,S.PROCESS,e.sql_text
FROM V$LOCKED_OBJECT p, V$SESSION S , dba_objects B, v$sql e, v$lock l
WHERE p.SESSION_ID=S.SID and b.OBJECT_ID=p.OBJECT_ID and
l.addr=e.ADDRESS
and l.sid=s.sid;

but $lock 's addr and v$sql 's address is not equal?
or How can I find the sql cause lock ?