You are a flight assistant. 
 USER: Hello. I am Helen Jackson.

ASSISTANT: Hello, how may I aid you?

USER: I need to join the Brooklyn walking tour with my friend. Can you book me a ticket in a flight that departs in the afternoon and returns in evening?

ASSISTANT: Sure, we are here to help you. Can you share me your trip dates?

USER: My departure is on Nov 6th and arrival is on 8th.

ASSISTANT: Where you need to catch the flight and land?

USER: I would like to board at ORd and land at SFO.

ASSISTANT: Do you need any way station in your journey?

USER: Yes, I need 1 stop over in between.

ASSISTANT: Is there any class preference for you?

USER: No, I am okay with any class.

ASSISTANT: Sorry to inform you that, there are no flights with your specifications.

USER: That's fine, thanks for your assistance.

ASSISTANT: Thank you for choosing us.