Check-in on line is never reliable. I had 2 flights, the system didn't allow me to do check-in for both in one log in (one after the other) so I had to do it for one, finish, be out of the system and log in again to do it for the second one. The problem is that, in addition to that, the web page is not stable or reliable. I logged in for the second time, chose seats and in the last stage of "sending the boarding ticket to my mail" the page didn't charge so I was left in a limbo. I tried to check in again and the system said I was already checked in. When I arrive to the airport I had no check in done for the second trip and lost the seat I had initially selected.