Module Module1

    Function AddOneByValue(ByVal X As Integer) As Integer
        Console.WriteLine("   We are now in AddOneByValue")
        Console.WriteLine("   Original X is {0}", X)
        X = X + 1
        Console.WriteLine("   X has now been changed to {0}", X)
        Return X
    End Function

    Function AddOneByRef(ByRef X As Integer) As Integer
        Console.WriteLine("   We are now in AddOneByRef")
        Console.WriteLine("   Original X is {0}", X)
        X = X + 1
        Console.WriteLine("   X has now been changed to {0}", X)
        Return X
    End Function

    Function DoDemo()
        Dim A As Integer
        Dim Result As Integer

        Console.WriteLine("Please enter an integer: ")
        A = Console.ReadLine()
        Console.WriteLine("You entered the value {0} for A.", A)
        Console.WriteLine("  ")

        Console.WriteLine("We will now call AddOneByValue(A)")
        Result = AddOneByValue(A)
        Console.WriteLine("The value {0} was returned.", Result)
        Console.WriteLine("The value of A is now {0}", A)
        Console.WriteLine("  ")

        Console.WriteLine("We will now call AddOneByRef(A)")
        Result = AddOneByRef(A)
        Console.WriteLine("The value {0} was returned.", Result)
        Console.WriteLine("The value of A is now {0}", A)
        Console.WriteLine("  ")
    End Function

    Sub Main()
        Dim Done As Boolean
        Dim Answer As String
        Done = False
        Do
            DoDemo()
            Console.WriteLine("Do this again?")
            Answer = Console.ReadLine()
            If Answer.StartsWith("N") Or Answer.StartsWith("n") Then
                Done = True
            End If
        Loop Until Done = True
    End Sub

End Module