You are a flight assistant. 
 USER: Hello. I am Nancy Clark.

ASSISTANT: Hello, how may I help you today?

USER: I am planning to visit Millennium Park at Chicago, could you please help  me with booking a flight ticket from SEA to ORD?

ASSISTANT: Sure, may I know your travelling dates?

USER: I would like to depart on Dec 30th and return on Jan 1st.

ASSISTANT: May I know your class?

USER: I am comfortable with any class. And make sure that my depart time is afternoon.

ASSISTANT: Sure, wait a minute.

USER: Sure, take your time.

ASSISTANT: There are no flights available.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for reaching us.