I'm traveling with my 5 year old grandson next week MSP to SEA, without his parents. What do I need in terms of identification or permission to take him with me. I know what's needed when leaving the country with a minor but what about state to state? TIA Btw, I used my AMX voucher and purchased two business class seats for the price of one. I'm sure I'll see a few eye-rolls when we take our seats but he's a very well-behaved kid and hopefully my cabin mates will not even remember he's there.