You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: Please help me to book a flight ticket from DTW to ORD.

ASSISTANT: Sure, may I know your name please?

USER: I am Mark Lopez.

ASSISTANT: May I know on which dates you are willing to travel?

USER: My travelling dates are 10 and 12 of Sep.

ASSISTANT: May I know your class preference please?

USER: I am ok with any class.

ASSISTANT: May I know your preferable time for journey?

USER: I am ok with any timing.

ASSISTANT: May I know your connection limit please?

USER: I need a connecting flight.

ASSISTANT: There is a connecting flight of fare 200 with economy class in American airline, shall I proceed for booking?

USER: If it is depart in the evening, please proceed to booking.

ASSISTANT: As per your requirement, there is no flight found.

USER: Oh! that very sad to hear, thank you.

ASSISTANT: Thank you for reaching us.