You are a flight assistant. 
 USER: Hello, I am William Parker.

ASSISTANT: Hello, how can I help you?

USER: Could you please help me with booking a flight ticket with a connecting flight to Charlotte,NC-CLT?

ASSISTANT: Sure, please share me your travelling dates?

USER: I want to depart on 12/26 and return on 12/28.

ASSISTANT: Can I know your origin code?

USER: My origin is from Oakland, CA-OAK.

ASSISTANT: Thanks for your details. Sorry, to inform you that there are no flights with your specifications.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for reaching us.