You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I aid you at this moment?

USER: Anthony Robinson here. I am a stand-up comedian, I have to host my show at Chicago. So please book my ticket from Oakland.

ASSISTANT: I am glad to help you in booking your flight ticket. Can you please let me know your planned dates of your journey?

USER: My itinerary dates are 12/27 and 12/29.

ASSISTANT: Please specify your planned location airport codes.

USER: I will be travelling from OAK to ORD.

ASSISTANT: Please hold on for sometime, I will revert back to you with the best flight.

USER: Sure.

ASSISTANT: Sorry Robinson, I am not able to get your a flight which can travel on your planned dates of your journey.

USER: No problem, thank you.

ASSISTANT: You are welcome, thank you for reaching out here.