You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Paul Green here. I want to attend a Seminar in Detroit. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, I am here to help you with that.

USER: Thanks.

ASSISTANT: Please share your depart and return dates.

USER: My travelling dates are 05/19 and 05/21.

ASSISTANT: What time are you looking for takeoff and return?

USER: I want to departure on afternoon.

ASSISTANT: Please share your source and destination airport codes.

USER: My airport codes are PHL and DTW.

ASSISTANT: Which class are you looking for your journey?

USER: I am comfortable with any class.

ASSISTANT: Do you have any other preference?

USER: I want to travel in single connecting flight.

ASSISTANT: Sure, please wait for a while.

USER: Ok, I will wait.

ASSISTANT: Sorry, we didn't find any flight which is running in the afternoon between given route.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for reaching us.