You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, In what way can I assist you now?

USER: Can you please help me to book a flight from DEN to ATL?

ASSISTANT: Sure, please share me your trip dates.

USER: I want to depart on July 19 and need to return on July 21.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a connecting flight.

ASSISTANT:  If you can help me with your name, I can begin looking up for the availability of flights.

USER: Kevin Martin here.

ASSISTANT: May I know if you prefer to have any other comforts in your journey?

USER: I do not have any other specifications.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for choosing us.