Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim ar As New ArrayList
        Dim l As Int32
        Dim max As Int32 = Convert.ToInt32(Me.TextBox1.Text)
        Const toNum As Integer = 20000
        Me.ProgressBar1.Value = 0
        Me.ProgressBar1.Maximum = max
        Me.ProgressBar1.Step = 1
        Randomize()
        If max > toNum Then
            MsgBox("das geht net")
            Exit Sub
        End If
        Do Until ar.Count = max ' ANZAHL D. DURCHLÄUFE
            l = toNum * Rnd() + 1 ' ZAHLEN ZWISCHEN %toNum und 1
            If Not ar.Contains(l) Then
                ar.Add(l)
                Me.ProgressBar1.PerformStep()
            End If
        Loop
        Me.ListBox1.Items.Clear() ' AUSGEBEN
        For Each o As Object In ar
            Me.ListBox1.Items.Add(o.ToString)
        Next
    End Sub