You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I have planned to book a ticket from OAK to LAS, can you assist me?

ASSISTANT: Sure, we are here to help you. Can you share me your travelling dates?

USER: My preferred dates are Feb 22nd and Feb 24th.

ASSISTANT: May I know your name?

USER: Stephen Walker.

ASSISTANT: Do you have any other specifications?

USER: Make sure that my return time must be afternoon.

ASSISTANT: Ok, wait for some time.

USER: Sure.

ASSISTANT: Thanks for waiting there are no flights found on your details.

USER: No problem, thank you for searching.

ASSISTANT: Thanks for approaching us.