conditional group summing problem

I am having a little difficulty with aggregate functions in a group. I have two columns, one for the current year and one for the previous year. the functions are as follows:

=Sum(iif(Fields!YEAR_DESIGNATION.Value="C",Fields!AMOUNT.Value,0)) // Current year sales

and

=Sum(iif(Fields!YEAR_DESIGNATION.Value="P",Fields!AMOUNT.Value,0)) // Previous year sales

The YEAR_DESIGNATION field is based on a sql server case statement that returns a "P" or a "C" depending on the year (invoice date). Anyway, the data looks perfectly normal, each row has a "P" or a "C" along with a value in the amount field. For some reason if the grouping contains both P" and "C" rows, I get #error where the data should be. If a row only contains all P's or all C's the totals work. I have done this before but for some reason I can't get this to work.

P.S. All fields have data (there are no nulls)

It sounds like the AMOUNT field value is not of type System.Int32, but either Int16 or Double or Decimal. Assuming you are conditionally aggregating double values, you have to ensure that the datatypes are always the same:

=Sum(iif(Fields!YEAR_DESIGNATION.Value="C", CDbl(Fields!AMOUNT.Value), 0.0))

-- Robert

|||That was it! Thanks again. Your always a very big help Robert.