A longtime local family travel agency has been sending "Greeks to Greece" for over 40 years on the same international airline out of Chicago to the same destination in Greece.The travel agent has never asked for nor had a written contract, but year in and year out has brought droves of families and generations as passengers to this airline on this route.The airlines appreciated his predictable and steady, repeat business.As such, every year the airline would reserve blocks of seats for this travel agent and just charge him the same price as the previous season.After the Olympics were announced to be hosted in Athens, Greece, the airline changed its local management and subsequently refused to honor the block of seats and prices given to the travel agent.This left the travel agent, who had confirmed clients and tour packages, with no way to get his customers to Greece.

Is there an enforceable contract, and if so, under what circumstances and terms? Please explain your answer.