I'm a international student who has a graduation tomorrow May 14. My dad who does not speak English at all came all the way from a different country and had a stop at ORD Mon May 12 afternoon. He was told he could get on the very next flight on T morning, but later the airline said there is no more seats available for him. I called over the airline and the representative said if I called earlier my dad could have a seat. I don't know how airline works nowadays.