Blocking Session Lockwait Best

SELECT TO_CHAR(sysdate, 'DD-MON-YYYY HH24:MI:SS')
|| ' User '
||s1.username
|| '@'
|| s1.machine
|| ' ( SID= '
|| s1.sid
|| ' ) with the statement: '
|| sqlt2.sql_text
||' is blocking the SQL statement on '
|| s2.username
|| '@'
|| s2.machine
|| ' ( SID='
|| s2.sid
|| ' ) blocked SQL -> '
||sqlt1.sql_text AS blocking_status
FROM v$lock l1, v$session s1, v$lock l2 ,
v$session s2,v$sql sqlt1, v$sql sqlt2
WHERE s1.sid =l1.sid
AND s2.sid =l2.sid AND sqlt1.sql_id= s2.sql_id AND sqlt2.sql_id= s1.prev_sql_id AND l1.BLOCK =1
AND l2.request > 0 AND l1.id1 = l2.id1 AND l2.id2 = l2.id2;