You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I guide you?

USER: I want to book a flight ticket from Oakland to attend an exam in Chicago, can you help me to book a flight ticket with single connection?

ASSISTANT: Sure, I can help you. Can I know your travelling dates?

USER: I need to depart on Oct 17th and my return date will be on Oct 19th.

ASSISTANT: Please share me your airport codes.

USER: My source point is OAK and my landing point is ORD.

ASSISTANT: Are you okay with an business class?

USER: Yes, I need a business class ticket.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT: May I know your name?

USER: I am Larry Campbell.

ASSISTANT:  We are unable to provide flight in between your journey routes due to some technical up-gradation at destination airport.

USER: No issues, I'll choose any alternative to reach my destination. Thank you.

ASSISTANT: Thank you for reaching us.