You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: Will you please book me a flight ticket from IAD to OAK?

ASSISTANT: Sure, May I know the travelling dates?

USER: I will start on Dec 1st and return on Dec 3rd.

ASSISTANT: Do you have any connection limit?

USER: I need 1 stop over within my route.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: I am Katherine Young.

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

USER: That's Ok, thanks for your support.

ASSISTANT: Thank you for availing us.