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

ASSISTANT: Hello, how can I support you for the day?

USER: I am planning to go for shopping in Oakland mall. Can you please help me with book a direct flight?

ASSISTANT: Sure, I am here to help you. Can you please help me with your airport codes?

USER: My source code is from Austin, TX - AUS to Oakland, CA - OAK.

ASSISTANT: May I know when you are willing to travel?

USER: My depart is on 05/31 and arrival on 06/02.

ASSISTANT: Do you have any other specification?

USER: My price limit is 500.

ASSISTANT: Please wait for a moment. Sorry, we found no flights with your specifications.

USER: OK, no problem I have to go with another flight.

ASSISTANT: Thank you for choosing us. hope to serve you better next time.

USER: Thanks for your information.