You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I am looking to book a flight ticket to meet my friend in Detroit. Can you help me for booking a flight ticket from IAD to DTW?

ASSISTANT: Sure, please share me your trip dates.

USER: My travelling dates are Jan 18 and Jan 20.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a single connecting flight.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: My name is Jennifer Robinson.

ASSISTANT: Do you have any particular time for departing and returning?

USER: No.

ASSISTANT: May I know your airline preferences?

USER: I have no airline preference. I prefer to book a economy class.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait for your response.

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

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for communicating with us.

USER: Welcome.