protected void btnCalcular_Click(object sender, EventArgs e)
    {
        try
        {
            Reserva res = new Reserva(11, clnFechaIn.SelectedDate, clnFechaFin.SelectedDate, "activa", (Cliente)Session["usuario"], ((Habitacion)Session["habReserva"]));
            Session["reserva"] = res;

            lblCosto2.Visible = true;
            lblCosto.Visible  = true;
            lblCosto.Text     = res.CalcularCosto().ToString() + "$";
        }

        catch (Exception ex)
        { lblMsj.Text = ex.Message; }
    }