You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Can you please help me to book a flight from PHX to OAK?

ASSISTANT: May I know your travel dates?

USER: Sure, I want to travel on Dec 16 and need to return on Dec 18.

ASSISTANT: Do you prefer connecting flight?

USER: I need a flight with single stopover.

ASSISTANT: Do you have any other specifications?

USER: I prefer economy class to travel.

ASSISTANT: May I know your good name?

USER: Margaret Campbell here.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for reaching us.