Private Sub ToppingCheckChanged(ByVal sender As System.Object, ByVal e As EventArgs)
        Me.ListBox1.Items.Clear()  'clear the ListBox before updating
        For Each chkbox As CheckBox In Me.fpmeat.Controls
            If chkbox.Checked Then
                Me.ListBox1.Items.Add(chkbox.Text)
            End If
        Next
        For Each chkbox As CheckBox In Me.fpveggie.Controls
            If chkbox.Checked Then
                Me.ListBox1.Items.Add(chkbox.Text)
            End If
        Next
        Me.Label1.Text = "Number of toppings: " & Me.ListBox1.Items.Count.ToString()
    End Sub