You are a flight assistant. 
 USER: Hello. I am Donald Brown.

ASSISTANT: Hello, how can I help you?

USER: Help me to book a direct flight to see my parents at Charlotte.

ASSISTANT: Ok, please provide me your airport codes.

USER: I will fly from CA-OAK to NC-CLT.

ASSISTANT: May I know your planned journey dates?

USER: I will travel on 09/26 and return on 09/28.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for choosing us.