Public Class Form2
    Public card As card
    Public parent As Form1
    Public Sub New(karta As card, form As Form1)

        ' To wywołanie jest wymagane przez projektanta.
        InitializeComponent()

        ' Dodaj inicjowanie po wywołaniu funkcji InitializeComponent().
        card = karta
        parent = form
    End Sub
    Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        MsgBox("your card balance is:" + vbNewLine + card.ammound.ToString)
        Me.Close()
    End Sub

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If card.ammound >= Int(TextBox1.Text) Then
            card.ammound = card.ammound - Int(TextBox1.Text)
            MsgBox("succesfully withdrawed: " + TextBox1.Text)
            Me.Close()
        Else
            MsgBox("not sufficient balanse")
            Me.Close()
        End If
    End Sub

    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
        card.ammound = card.ammound + Int(TextBox2.Text)
        MsgBox("succesfully deposited: " + TextBox2.Text)
        Me.Close()
    End Sub

    Private Sub Button5_Click(sender As Object, e As EventArgs) Handles Button5.Click
        Dim cardl = TextBox4.Text
        Dim ammound = Int(TextBox5.Text)
        If card.ammound >= ammound Then
            Dim found As Integer = -1
            For i = 0 To parent.karty.Length - 1
                If cardl = parent.karty(i).numer Then
                    found = i
                End If
            Next
            If found = -1 Then
                MsgBox("target card not exists")
                Me.Close()
                Return
            End If
            card.ammound = card.ammound - ammound
            parent.karty(found).ammound = parent.karty(found).ammound + ammound
            MsgBox("succesfully transfered to card: " + cardl + vbNewLine + "amound: " + ammound.ToString)

            Me.Close()
            Else
                MsgBox("not sufficient balanse")
            Me.Close()
        End If
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        If card.ammound >= Int(TextBox3.Text) Then
            card.ammound = card.ammound - Int(TextBox3.Text)
            MsgBox("succesfully topupped: " + TextBox3.Text + vbNewLine + "your code: " + GenerateRandomString(8, False))
            Me.Close()
        Else
            MsgBox("not sufficient balanse")
            Me.Close()
        End If
    End Sub

    Public Function GenerateRandomString(ByRef len As Integer, ByRef upper As Boolean) As String
        Dim rand As New Random()
        Dim allowableChars() As Char = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLOMNOPQRSTUVWXYZ0123456789".ToCharArray()
        Dim final As String = String.Empty
        For i As Integer = 0 To len - 1
            final += allowableChars(rand.Next(allowableChars.Length - 1))
        Next

        Return IIf(upper, final.ToUpper(), final)
    End Function
End Class