Public Class Form1



    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'Here I am declairing my variables'
        Dim name As String = TxtName.Text
        Dim postcode As String = txtPost.Text
        Dim cardnumber(7) As String
        Dim expiryDate As Date = DateTimePicker1.Text
        Dim todayDate As Date = Today
        Dim b As Integer
        Dim check_digit As Integer
        Dim s As Integer
        Dim storage(6) As String
        Dim h As Integer
        Dim total As Integer = 0
        Dim sum As Integer
        Dim valid As String
        Dim expired As String = ""
        Dim cardNostring As String


        'Here i am creating a loop'
        For b = 0 To 7
            cardnumber(b) = TxtNumber.Text(b)
        Next b

        check_digit = cardnumber(7)

        For s = 0 To 6
            storage(s) = TxtNumber.Text(s)
        Next s

        Array.Reverse(storage)

        storage(0) = storage(0) * 2
        If storage(0) > 9 Then
            storage(0) = storage(0) - 9
        End If

        storage(2) = storage(2) * 2
        If storage(2) > 9 Then
            storage(2) = storage(2) - 9
        End If

        storage(4) = storage(4) * 2
        If storage(4) > 9 Then
            storage(4) = storage(4) - 9
        End If


        storage(6) = storage(6) * 2
        If storage(6) > 9 Then
            storage(6) = storage(6) - 9
        End If

        MessageBox.Show(storage(0) & storage(2) & storage(4) & storage(6))

        For h = 0 To 6
            total = total + storage(h)
        Next h

        sum = total + check_digit

        If sum Mod 10 = 0 Then
            valid = "true"
        Else
            valid = "false"
        End If

        If expiryDate < todayDate Then
            expired = "true"
        ElseIf expiryDate > todayDate Then
            expired = "false"
        End If

        If valid = "false" Then
            Label7.ForeColor = Color.Red
            Label7.Text = "Card number invalid"
        ElseIf valid = "true" Then
            Label7.ForeColor = Color.Green
            Label7.Text = "Card number valid"
        End If

        If expiryDate < todayDate Then
            expired = "true"
        ElseIf expiryDate < todayDate Then
            expired = "false"
        End If

        If expired = "true" Then
            Label8.ForeColor = Color.Red
            Label8.Text = "card expired"
        ElseIf expired = "false" Then
            Label8.ForeColor = Color.Green
            Label8.Text = "Card not expired"
        End If

        If valid = "true" And expired = "false" Then
            MessageBox.Show("Card valid")
        Else
            MessageBox.Show("Card invalid")
        End If





        MessageBox.Show("name = " & name)
        expired = "false"


        cardNostring = TxtNumber.Text
        MessageBox.Show("postcode =" & postcode)
        MessageBox.Show("Card number =" & cardNostring)
        MessageBox.Show("Expirydate =" & expiryDate)










    End Sub


    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnClear.Click
        'here i am clearing the data of the textboxes and labels after they have been used.
        TxtName.Clear()
        txtPost.Clear()
        TxtNumber.Clear()
        Label7.Text = ""
        Label8.Text = ""
        DateTimePicker1.Text = Today
    End Sub
End Class