Hope this helps !
Sonia !
1) The query you have posted doesn't seem to work alteast on my system! Can u check and post the appropriate query using CONNECT clause !
2) As u require the nth maximum.. the query below will help you. Pass the required value for 'n'
Ales !
If I am right, your query will help in finding the 'n'th value, but not the 'n'th maximum value... correct me if I am wrong!
Pls. check out if the following is a soln.,
select * from (select sal, rownum rno from (select distinct sal
from t_emp order by sal desc))
where rno = &n
Cheers,
Nandu

Never give up !
Nanda Kumar - Vellore