private void loginButton_Click(object sender, EventArgs e)
        {
            LoginForm log = new LoginForm();

            log.ShowDialog();

            if (GlobalConfig.GuestUser != -1) // Guest logged in
            {
                GuestForm form = new GuestForm();
                form.ShowDialog();
            }
            else if (GlobalConfig.OwnerUser != -1) // Owner logged in
            {
                BusOwnerForm form = new BusOwnerForm();
                form.ShowDialog();
            }
        }
        private void registerSubmit_Click(object sender, EventArgs e)
        {
            if (!ValidInformation())
            {
                System.Windows.Forms.MessageBox.Show("Invalid information.\nPlease try again!");
                return;
            }

            if (GlobalConfig.Guest_byUsername(username.Text).Count > 0 ||
                GlobalConfig.Owner_byUsername(username.Text).Count > 0)
            {
                System.Windows.Forms.MessageBox.Show("This username has been used.\nPlease try a different one!");
            }
            else
            {
                OwnerModel aguest = new OwnerModel(name.Text, phonenumber.Text, username.Text, password.Text);
                GlobalConfig.Owners.Add(aguest);
                GlobalConfig.OwnerUser = aguest.Id;

                this.Close();
                BusOwnerForm form = new BusOwnerForm();
                form.ShowDialog();
            }
        }