You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Charles Brown. Can you please book a flight ticket from DTW to DCA?

ASSISTANT: Sure, May I know your journey dates?

USER: I would like to start on Aug 13 and return on Aug 15.

ASSISTANT: In which class do you want to travel?

USER: I am comfortable with any of the class.

ASSISTANT: Do you have any preferences?

USER: Yes, I need direct flight.

ASSISTANT: You have a flight 1016 in Delta airline and price 100 with a connection, Shall I proceed?

USER: Sorry, I need direct flight.

ASSISTANT: Ok. There is no direct flight available to your destination.

USER: It's ok, thank you for the information.

ASSISTANT: Thanks for reaching us.