private void metroLink1_Click(object sender, EventArgs e)
        {
            this.Hide();
            Rental_Management_DashBoard sp = new Rental_Management_DashBoard();

            sp.ShowDialog();
        }
        private void RentalTile_Click(object sender, EventArgs e)
        {
            this.Hide();
            Rental_Management_DashBoard rt = new Rental_Management_DashBoard();

            rt.ShowDialog();
        }