Other issues arise when it comes to leap years. The following code takes care of all the problems mentioned above:

VB .NET

Public Enum LicensePaymentType As Integer
  Monthly = 1
  Annual = 2
End Enum   

Private Function determineNextInvoice(ByVal LicType As LicensePaymentType, _
          ByVal InvoiceDay As Integer, ByVal LastInvoice As DateTime) As DateTime
  If LicType = LicensePaymentType.Monthly Then
     If LastInvoice.Day < InvoiceDay Then
        Dim Temp As Integer = InvoiceDay - LastInvoice.Day
        Dim NewInvDate As DateTime = LastInvoice.AddMonths(1)
        Return NewInvDate.AddDays(Temp)
     Else
        Return LastInvoice.AddMonths(1)
     End If
  ElseIf LicType = LicensePaymentType.Annual Then
     Dim NumDaysNextYearsMonth As Integer = _
           DateTime.DaysInMonth(LastInvoice.AddYears(1).Year, LastInvoice.AddYears(1).Month)
     If LastInvoice.Day < InvoiceDay AndAlso NumDaysNextYearsMonth >= InvoiceDay Then
        Dim Temp As Integer = InvoiceDay - LastInvoice.Day
        Dim NewInvDate As DateTime = LastInvoice.AddYears(1)
        Return NewInvDate.AddDays(Temp)
     Else
     Return LastInvoice.AddYears(1)
     End If
  End If
End Function

VB .NET

Dim newstr As String
newstr = oldstr.Replace(Chr(147), "& quot;") ' take out extra space b/w & and quot;
newstr = newstr.Replace(Chr(148), "& quot;") ' take out extra space b/w & and quot;

C#

string newstr;
newstr = oldstr.Replace((char)147, "& quot;") // take out extra space b/w & and quot;
newstr = newstr.Replace((char)148, "& quot;") // take out extra space b/w & and quot;

The first part (published today) gives an overview of what exactly is encryption, what are its properties, how can it be used, and what facilities SQL Server 2005 offers to help one create a cryptosystem.

In part two, we go over SQL Server 2005′s key hierarchy, and T-SQL functions and statements that can be used with symmetric keys to encrypt/decrypt data.

Part three, will introduce asymmetric encryption in SQL Server 2005, and how one can retrieve and send ecrypted data to/from an ASP .NET v2.0 web page.
Hope you enjoy them!

Update 2/28/2007: The final and third part of this article series has been posted entitled, “Using Asymmetric Encryption and Digital Signatures in a SQL Server 2005 Database“.

Update 2/21/2007: The second part of the three part series has been been posted entitled, “Using Symmetric Encryption in a SQL Server 2005 Database“.

Pretty neat stuff. I hope this catches on with a lot of existing and new sites. Check out this video for a preview on how it works.