You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I address you?

USER: I am Eric Lopez. I need a direct flight to attend a client meeting in Chicago, so please book a flight ticket from Seattle.

ASSISTANT: Sure, may I know your travelling dates?

USER: I will start on 12/31, return on 01/02.

ASSISTANT: Can you please share your journey codes?

USER: My source and destination airport codes are SEA, ORD.

ASSISTANT: Thanks for the information, please wait.

USER: Sure.

ASSISTANT: Unfortunately, there is no flight available with your requirements.

USER: No problem, thank you.

ASSISTANT: Thanks for reaching us.