I'm going KL 635, AMS to Las Vegas tomorrow. I'm going from DUB to AMS, then an hour layover and then the LAS flight. 787 in Economy. Is it possible, if I'm checking expert flyer and the online check in, that I can ask the desk at DUB to change my seat to any empty rows? Is that possible and if so can I do it from the check in desk at DUB?