Error help

[David Ebert]

Why do I get the error "Illegal column specification (2512)" on the following:   select weeknum, (sum(unit)) from vuservweek group by weeknum having costcent = 30 If I drop the HAVING clause I get results.  There IS a costcent = 30 in the view and the column is spelled correctly.   tia   Dave Ebert [EMAIL PROTECTED]