use of except

[Quoted] I would appreciate if someone could help me fix the following sql query.

The goal of the query is to find those years and months where a total is either less than 50 or more than 100.

SELECT month, year, MAX(nsick)
FROM sick
GROUP BY month, year
EXCEPT
SELECT month, year, MAX(nsick)
FROM sick
GROUP BY month, year
HAVING MAX(nsick)>50 AND MAX(nsick)<100;

I get the following error message:
EXCEPT
*
ERROR at line 4:
ORA-00933: SQL command not properly ended

Thanks in advance Received on Mon Oct 17 2011 - 04:39:35 CEST