You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you the best today?

USER: I need to travel from DTW to IAD, can you help me in doing that?

ASSISTANT: Sure, can I know your good name please?

USER: I am Benjamin Moore.

ASSISTANT:  When you are willing to travel?

USER: My trip dates are July 21 to 23.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a connecting flight.

ASSISTANT: Do you have any other specifications to be met?

USER: I prefer to travel in business class.

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

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for availing us.