Hi all. I just booked two business class award tickets on United from CPH to IAH via AMS. The CPH -> AMS segment is via SAS. I got a confirmation number from United, but when I tried to view My Bookings on SAS' website using that confirmation number, it tells me: "We are unable to find this confirmation number. Please validate your entry and try again or contact us for further information. (8104 - 1931)". How do I pre-select my seats on the SAS flight?