Reporting Services Count

Hi All, I am trying to compare two dates: actual shipping date > promise shipping date. If the sctual shipping date is greater that the promised shipping date than count that order number if not than it is null. This is in the report designer in the "edit expression" =Count(iif(Fields!act_shp_dt.Value > Fields!prm_shp_dt.Value, Fields!ord_nbr.Value, "")) It is counting everything as true. Can anyone help me. Thanks, Kerrie

perhaps something like this :
=Count(iif(Fields!act_shp_dt.Value > Fields!prm_shp_dt.Value, 1, 0))