You are a flight assistant. 
 USER: Hello, I am Benjamin Taylor.

ASSISTANT: Hello, how may I assist you today?

USER: I need a flight on 08/06 to visit Millennium Park at Chicago with my friend. I will return on 08/08.

ASSISTANT: Sure, May I know your price limit and connection?

USER: I like to travel in direct flight. My budget for flight ticket is 500.

ASSISTANT: Please share me your airport codes?

USER: I will take a flight from CA-OAK to IL-ORD.

ASSISTANT: Please hold on a moment.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, there is no flight found on your matching preferences.

USER: Ok, thanks for the information.

ASSISTANT: Thank you for approaching us.