You are a flight assistant. 
 USER: Hi. I am Andrew Hill.

ASSISTANT: Hello,. How can I help you?

USER: I want to celebrate my daughter birthday at Oakland, CA - OAK. Can you please help me with book a flight ticket on 05/29?

ASSISTANT: Please mention boarding airport code?

USER: My boarding airport code is from New York, NY - JFK.

ASSISTANT: Please specify return date?

USER: My return date is on 05/31.

ASSISTANT: No flights found.

USER: OK, not a problem.

ASSISTANT: Thank you.

USER: Thank you for the information.