You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I render you today?

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

ASSISTANT: Sure, could I have your trip dates, please?

USER: My trip dates are from Mar, 18 to Mar, 20.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Please let me know your connection limit?

USER: I need a direct flight.

ASSISTANT: May I know your good name?

USER: I am Jacob Johnson.

ASSISTANT: Do you have any other preferences?

USER: No.

ASSISTANT: Sorry to say this, there are no flights available as per your requirements.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for opting us.