vb.net night rider car display code

Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        Static Dim BoolArray(9) As Boolean
        Static Dim counter As Integer = 0
        Static Dim toAdd As Integer = 1
        BoolArray(counter) = False
        counter += toAdd
        BoolArray(counter) = True
        If counter > 8 Then
            toAdd = -1
        ElseIf counter < 1 Then
            toAdd = 1
        End If
        Dim NightRider As String = ""
        For index = 0 To BoolArray.Length - 1
            If BoolArray(index) Then
                NightRider &= "1"
            Else
                NightRider &= "0"

            End If
        Next
        TextBox3.Text = NightRider
    End Sub