You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I would like to book a ticket from PHL to DEN. Could you book a ticket?

ASSISTANT: Sure, may I know the travelling dates?

USER: Travelling dates are from Nov, 15 to Nov, 17.

ASSISTANT: Do you have any connection limit?

USER: I would be comfortable with single stop over.

ASSISTANT: Are there any other requirements?

USER: I prefer business class.

ASSISTANT: May I know your name?

USER: My name is Jonathan Lewis.

ASSISTANT: Sorry, no flights found with your chosen dates.

USER: Thank you.

ASSISTANT: Thank you for opting us.