You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Timothy Garcia here.

ASSISTANT: How can I help you?

USER: Can you book a flight ticket for my airport codes that is from DCA to ORD?

ASSISTANT: Sure. May I know your depart and arrival dates?

USER: The travel dates are from Apr 20 to Apr 22.

ASSISTANT: Can I have your good name?

USER: I am Timothy Garcia.

ASSISTANT: Let me know your connection limit.

USER: I am looking for a single connecting flight.

ASSISTANT: Do you have any other requirements?

USER: I would like to prefer a economy class.

ASSISTANT: Please, wait a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, there were no flights available on your preferred journey dates.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for reaching us.