private void button3_Click(object sender, EventArgs e)
        {
            this.Hide();
            Inregistrare f = new Inregistrare();

            f.Show();
        }
        private void pictureBox2_Click(object sender, EventArgs e)
        {
            this.Hide();
            Inregistrare f = new Inregistrare();

            f.Show();
        }