You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Catherine Thompson. I would like to book a direct flight. Could you please help me with booking a flight ticket?

ASSISTANT: Sure, please share your planned travel dates.

USER: Sure, my travelling dates are June 19 and June 21.

ASSISTANT: May I know your source and destination airport codes?

USER: Sure, LAS and OAK are my airport codes.

ASSISTANT: Do you have any other preference?

USER: Yes, I want to depart in the morning.

ASSISTANT: Sorry, we don't have any flight available in the morning from LAS to OAK.

USER: No worries, thank you for the information.

ASSISTANT: Thank you.