private void noToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Noliktava pro = new Noliktava();

            this.Hide();
            pro.Show();
        }
        private void button2_Click(object sender, EventArgs e)
        {
            Noliktava pro = new Noliktava();

            // pro.MdiParent = this;
            this.Hide();
            pro.Show();
        }