You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Can you please book a flight ticket from DEN to DFW?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Thank you. I have planned my travel dates as May 12 and May 14.

ASSISTANT: Can I know your name please?

USER: Sure, myself Matthew Hall.

ASSISTANT: Do you need any specifications in airlines?

USER: Yes, I am looking for single connecting flight.

ASSISTANT: Can I know your other preferences?

USER: I do not have any other specifications.

ASSISTANT: Sorry, there are no flights found.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you for reaching us.

USER: Most welcome.