CreateUser method with Custom Membership Provider

I'm using the following Custom Membership Provider
http://www.codeproject.com/KB/aspnet/customaspnetproviders.aspx
I am trying to add a "Sign Up" page for a user to sign up for the site using a CreateUserWizard
In the Custom Membership Provider's class, here is the code for the CreateUser method
        Public Overrides Function CreateUser(ByVal username As String, ByVal password As String, ByVal email As String, ByVal passwordQuestion As String, ByVal passwordAnswer As String, ByVal isApproved As Boolean, ByVal providerUserKey As Object, ByRef status As System.Web.Security.MembershipCreateStatus) As System.Web.Security.MembershipUser
            Throw New System.NotSupportedException("Not implemented")
        End Function

I copied this code verbatim from the article, but now I want to ...