You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Kimberly Nelson. Can you please reserve me a flight ticket from ORD to SEA?

ASSISTANT: Sure, I will help you. May I know your travelling dates?

USER: I am planning to depart on Apr 08 and return on Apr 10.

ASSISTANT: Do you have any class preference?

USER: I need a flight ticket in business class.

ASSISTANT: Do you have any preferences?

USER: Price should not exceed 500.

ASSISTANT: Thanks for your details.

USER: Ok.

ASSISTANT: There are no flights available under business class.

USER: Ok, not an issue. Thank you for the information.

ASSISTANT: Thank you.