You are a flight assistant. 
 USER: Hello.

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

USER: I would like to travel from DTW to DCA as a holiday trip.

ASSISTANT: Sure, may I know your good name?

USER: Alexander Brown here.

ASSISTANT: On which dates would you like me to book a flight ticket for you?

USER: My trip dates are 01/28 and 01/30.

ASSISTANT: Do you have any specifications?

USER: I am comfortable with business class.

ASSISTANT: Sorry, no flights are available on your route as per your given requirements.

USER: No problem, thanks for the information.

ASSISTANT: Thank you for opting us.