private void btn_nuevo_Click(object sender, EventArgs e)
{
//_DB.cerrar_transaccion();
_DB.iniciar_transaccion();
this.lbl_estado.Visible = true;
this.lbl_estado.Text = "Transacción iniciada";
this.btn_grabar.Enabled = true;
this.btn_actualizar.Enabled = true;
this.Dgv_habitacion.Enabled = true;
this.Dgv_huesped.Enabled = true;
this.Dgv_Instalacion.Enabled = true;
this.Dgv_Servicio.Enabled = true;
this.cmb_hotel.Enabled = true;
this.btn_buscar.Enabled = true;
this.btn_nuevo.Enabled = false;
//this.btn_volver.Enabled = false;
}