You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How can I aid you?

USER: I am Rebecca Williams. Could you please book a flight ticket to Oakland on 12/17 and return on 12/19?

ASSISTANT: May I know your travel points?

USER: My journey airport codes are DFW and OAK.

ASSISTANT: Do you have any preference?

USER: I need a way station in between my journey.

ASSISTANT: Sorry, no flights are available on your travel dates.

USER: No problem, thank you for the information.

ASSISTANT:  Thank you for availing us.