You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Karen Young.

ASSISTANT: How may I assist you?

USER: I want to book a ticket from LAS to LGA, can you please book a ticket?

ASSISTANT: At what time do you like to travel?

USER: I want to return at afternoon.

ASSISTANT: Do you have any specifications?

USER: I need a business class.

ASSISTANT: May I know your travel dates?

USER: My travelling dates are on Sept 05 and Sept 07.

ASSISTANT: Sorry, there is no flight on your details.

USER: Ok, not a problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you.