private void buttonNaslovna_Click(object sender, EventArgs e)
        {
            panel2.Height = buttonNaslovna.Height;
            panel2.Top    = buttonNaslovna.Top;
            kampusGymHome n = new kampusGymHome();

            n.Show();
            this.Hide();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            k.username = textBox1.Text;
            k.password = textBox2.Text;

            bool success = b.loginCheck(k);

            if (success)
            {
                MessageBox.Show("Prijava uspješna", "Obavijest");
                if (k.username == "admin" || k.username == "user")
                {
                    kampusGymHome au = new kampusGymHome();
                    au.Show();
                    this.Hide();
                }
            }
            else
            {
                //login failed
                MessageBox.Show("Prijava neuspješna. Pokušajte ponovo.");
            }
        }