You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Karen Martinez. Can you please reserve me a flight ticket from DCA to MCO?

ASSISTANT: Sure, may I know your trip dates?

USER: My trip dates are July 07 and July 09.

ASSISTANT: May I know your other requirements?

USER: I prefer to depart in the afternoon time.

ASSISTANT: Can I know your class?

USER: No.

ASSISTANT: There are no flights available on your travelling dates.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.