  private void Reverse_Click(object sender, EventArgs e)
        {
            Random r1 = new Random();
            Random r = new Random(r1.Next());
            int max = r1.Next(100);
            int[] a1 = new int[max];
            int[] a = new int[max];
            listBox1.Items.Clear();
            listBox2.Items.Clear();
            for (int i = 0; i < a.Length; i++)
                a[i] = r.Next(1000);
            for (int i = 0; i < a.Length; i++)
                listBox1.Items.Add(a[i].ToString());
            Array.Reverse(a, 0, max);
            for (int i = 0; i < a.Length; i++)
                listBox2.Items.Add(a[i].ToString());
        }
