You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Nancy Johnson.

ASSISTANT: How can I aid you at this moment?

USER: I want to book a ticket from ORD to SFO to attend seminar, can you help me in booking?

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

USER: I am departing on Sep 15 and return on Sep 17.

ASSISTANT: Do you have any connection limit for this journey?

USER: I need a flight with connection limit 1.

ASSISTANT: May I know your airline preference for this journey?

USER: I am ok with any airlines.

ASSISTANT: Do you have any class preference for this journey?

USER: I am comfortable with any class.

ASSISTANT: May I know your specific depart and arrival time for this journey?

USER: I want to depart in evening.

ASSISTANT: Nancy Johnson, there are no flight services available with your preferences on this route on your provided dates.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for opting us.