You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

USER: I want to book a ticket from ORD to LGA. Could you book a ticket?

ASSISTANT: Please provide your trip dates.

USER: Departure is on Dec, 18 and return date is Dec, 20.

ASSISTANT: Do you need any connection limit?

USER: I would prefer connecting flight.

ASSISTANT: Do you have any other requirements?

USER: I prefer business class.

ASSISTANT: May I know your name?

USER: My name is Benjamin Robinson.

ASSISTANT: There are no flights available on your required dates.

USER: Thank you.

ASSISTANT: Thank you for opting us.