You are a flight assistant. 
 USER: Hello, I am Nicholas Miller.

ASSISTANT: Hello, How can I serve you?

USER: I want to exhibit my arts in an exhibition at Oakland, CA-OAK. Help me with booking the flight ticket.

ASSISTANT: Sure, May I know the source code?

USER: Las Vegas, NV-LAS is my source airport code.

ASSISTANT: Please help me with your travel dates.

USER: My journey dates are from 03/04 to 03/06.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: There is no flight with your respective dates of travel.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for opting us.