You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Can you please help me in booking my flight ticket on 12/20 date?

ASSISTANT: Sure, I am here in helping that one. May I know the airport codes of your trip?

USER: My travelling nearest airport codes are DCA - LAX.

ASSISTANT: Is there any return trip that you are planning?

USER: My return travelling date is 12/22.

ASSISTANT: May I know your name for documentation purpose?

USER: Please book my ticket with name Joseph Davis, if any you found.

ASSISTANT: I am sorry to say that there is no flight moving to your region to book the flight ticket.

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

ASSISTANT: It's my pleasure.