Module Module1
    ' recursive function to find factorial n
    Function calcFactorial(ByVal n As Integer) As Integer
        Dim factorial As Integer

        Console.WriteLine(String.Format("n={0}", n))
        If (n = 0) Then
            factorial = 1
        Else
            factorial = n * calcFactorial(n - 1)
        End If

        Console.WriteLine(String.Format("At line A {0}", factorial))
        Return factorial
    End Function

    Sub Main()
        Dim x As Integer
        Dim eat As String

        x = calcFactorial(4)
        Console.WriteLine(String.Format("At line B {0}", x))

        Console.WriteLine("Any key to continue")
        eat = Console.ReadLine()
    End Sub

End Module