Public Class Form1
    Dim spis(6) As String
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        clearList()
        Array.Sort(spis)
        For Each item As String In spis
            ListBox1.Items.Add(item)
        Next

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        clearList()
        spis(0) = "Английски език"
        spis(1) = "Български език"
        spis(2) = "Математика"
        spis(3) = "История"
        spis(4) = "Физика"
        spis(5) = "Химия"
        spis(6) = "Биология"
        For Each item As String In spis
            ListBox1.Items.Add(item)
        Next

    End Sub
    Private Sub clearList()
        ListBox1.Items.Clear()
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        clearList()
        Array.Reverse(spis)
        For Each item As String In spis
            ListBox1.Items.Add(item)
        Next
    End Sub
End Class