You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am planning to visit Seattle, WA-SEA. Can you please help me for booking the flight ticket from Las Vegas?

ASSISTANT: Ok, may I know your source code?

USER: The source code is from NV-LAS.

ASSISTANT: Ok, please mention your trip dates.

USER: The departure date is 11/10 and the return date is 11/12.

ASSISTANT: Ok, may I know your name?

USER: Sure, my name is Paul Wilson.

ASSISTANT: Ok, there is no flight on your route.

USER: Ok, no problem.

ASSISTANT: Thanks for choosing us.

USER: Thank you for your information.