You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: I would like to attend a cultural event at Las Vegas, can you help me to book a flight ticket from OAK to LAS?

ASSISTANT: Sure, May I know the travelling dates?

USER: I want to take off on 27 Oct and return on 29 Oct.

ASSISTANT: Do you have any connection limit?

USER: I want a connecting flight.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: I am Dennis Miller.

ASSISTANT: Please wait a minute.

USER: Sure.

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

USER: It's ok, not a problem, thank you.

ASSISTANT: Thank you for opting us.