You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to attend a Seminar in Denver. Can you please help me for booking the flight ticket?

ASSISTANT: Yes, can you tell me your dates of travel?

USER: My travelling dates are Jan 04 and Jan 06.

ASSISTANT: Can I know your nearest airport codes?

USER: My airport codes are ORD and DEN.

ASSISTANT: Do you have any other preferences?

USER: I don't have any other preferences.

ASSISTANT: Give me a moment.

USER: Ok, I will wait.

ASSISTANT: Sorry to inform you that there are no flights found on your requested dates.

USER: Anyway, thanks for the information.

ASSISTANT: Can I know your name?

USER: Gary Roberts.

ASSISTANT: Thank you for contacting us.