You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Richard Green. I want to book a flight ticket to attend Charlotte International Auto Show, they are exhibiting more than 400 vehicles from many branded companies. Could you please help me in booking a ticket on 03/27 and 03/29?

ASSISTANT: Sure Green, can I know the airport codes please?

USER: My airport codes are OAK and MCO.

ASSISTANT: Sorry, there are no flights available on your dates.

USER: No problem, thank you for your valuable information.

ASSISTANT: Thank you for approaching us.