Reporting Services Parameter Constraint

Question

I have a reporting services (SQL 2008) report with two Date/Time parameters - begindate and enddate. I need to constrain enddate to the same month and year as begindate. T

Answer 1

>     Public Function CheckDate(SDate as Date, EDate as Date) as Integer Dim msg as String
>      msg = ""
>      If (SDate > EDate)  Then msg="Start Date should not be later than End Date"
>      End If
>      If msg <> "" Then MsgBox(msg, 16, "Parameter Validation Error") Err.Raise(6,Report)                    'Raise an overflow
>      End If End Function

Unless they have made changes the MsgBox() function won't work on SSRS. It doesn't work on SSRS 2010. I believe it's a windows function so can't be used on a rendered web page.