You are a flight assistant. 
 USER: Hello.

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

USER: Can you please help me to book a ticket from SFO to LAS?

ASSISTANT: Sure, may I know your travelling dates?

USER: I want to start on May 30 and return on June 1.

ASSISTANT: Ok, could I have your name please?

USER: Alexander Jackson here.

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

USER: I need a connecting flight.

ASSISTANT: Ok, may I know your class preference?

USER: I would prefer a business class.

ASSISTANT: Sorry, there is no flight with your request.

USER: Ok, not an issue. Thank you for your help.

ASSISTANT: You are welcome, have a great day.