Custom Code in SSRS 2008

Question

Hi,
I am trying to write Custom Code in SSRS for Age Calculation for two requirements in the same report,But report is giving error #Error in expression with my below code.
whole logic is same for both but only two lines are different,Do i need create two functions or can i use them in one function.Please guide me.
1)Age in Years (Ex: 4)
2) Age in Years + months (ex: 3 Years 6 months)
My SSRS Custom Code:
Public Shared Dim Years as Integer
Public Shared Dim Months as Integer
Public Shared Dim Days as Integer
Public Shared Dim Age as Integer
Public Shared Function CalAge(ByVal D1 As Datetime,ByVal D2 As Datetime ) As Integer
  Years=Year(D1)-Year(D2)
  Months=Month(D1)-Month(D2)
  Days=Day(D1)-Day(D2)
       If Days < 0 then 
           Months=Months-1
         End if
       If Months < 0 then 
          Years=Years-1
         End if
       If Months < 0 then
          Months=Months+12
       End If
     Return Years 
If Months=1 then
    Age=Years+" Years " + Months + "Month"
else
  Age=Years+" Years " + Months + "Months" 
End If 
Return Age
  End Function

Answer 1

hi Guys,
I have finally changed my custom code to below :
Public Shared Dim Years as Integer
Public Shared Dim Months as Integer
Public Shared Dim Days as Integer
Public Shared Function CalAge(ByVal D1 As Datetime,ByVal D2 As Datetime ) As Integer
  Days=DatePart(DateInterval.Day,D1)-DatePart(DateInterval.Day,D2)
 Months=DatePart(DateInterval.Month,D1)-DatePart(DateInterval.Month,D2)
  Years=DatePart(DateInterval.Year,D1)-DatePart(DateInterval.Year,D2)
         If Days < 0 then 
           Months=Months-1
      End If
       If Months < 0 then 
          Years=Years-1
        End If
       If Months < 0 then
          Months=Months+12
       End If
     Return Years 
  End Function
Public Shared Function CalMon(ByVal D3 As Datetime,ByVal D4 As Datetime ) As Integer
   Days=DatePart(DateInterval.Day,D3)-DatePart(DateInterval.Day,D4)
   Months=DatePart(DateInterval.Month,D3)-DatePart(DateInterval.Month,D4)
  Years=DatePart(DateInterval.Year,D3)-DatePart(DateInterval.Year,D4)
     If Days < 0 then 
           Months=Months-1
      End If
       If Months < 0 then 
          Years=Years-1
        End If
       If Months < 0 then
          Months=Months+12
       End If
 Return Months 
  End Function
and using expression in SSRS fo display like this  :
=IIF((Code.CalMon(Parameters!AgeCalcDate.Value,Fields!StudentBirthDate.Value))=1,Code.CalAge(Parameters!AgeCalcDate.Value,Fields!StudentBirthDate.Value) & " Years " & Code.CalMon(Parameters!AgeCalcDate.Value,Fields!StudentBirthDate.Value)
& " Month ",
    Code.CalAge(Parameters!AgeCalcDate.Value,Fields!StudentBirthDate.Value) & " Years " & Code.CalMon(Parameters!AgeCalcDate.Value,Fields!StudentBirthDate.Value) & " Months ")
got the correct solution.