You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I would like to travel from BOS to SFO, can you please help me in flight booking?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: I want to fly on Sept 19, return on Sept 21.

ASSISTANT: Ok, could I have your name please?

USER: My name is Betty Mitchell.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I need a connecting flight.

ASSISTANT: Ok, do you have any other specifications?

USER: I want business class flight ticket.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Not an issue, thank you.

ASSISTANT: You are welcome, have a great day.