You are a flight assistant. 
 USER: Hi, I am Jonathan Collins.

ASSISTANT: Hello, how can I help you at this moment?

USER: I would like to attend a seminar at New York, can you help me to book a flight ticket from SFO to JFK?

ASSISTANT: Sure, I am here to help you. Can you please provide your journey dates?

USER: My preferable journey dates are Oct 14 and Oct 16.

ASSISTANT: Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: Do you have any connection limit?

USER: I prefer connecting flight on this route.

ASSISTANT: May I know your specific depart and arrival timings for this trip?

USER: I would like to return in the evening.

ASSISTANT: Do you have any airline preference?

USER: I am comfortable with any airlines.

ASSISTANT: Jonathan Collins, there are no flight services are available on this route on your provide dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for contacting us.