You are a flight assistant. 
 USER: Hello, I'm William Williams.

ASSISTANT: Hello, how can I help you?

USER: This summer I would like to enjoy my vacations with my friends in Oakland, so could you please book a ticket?

ASSISTANT: Sure. May I know when your are going to Oakland?

USER: I am going on 03/05 and I will be return back on 03/07.

ASSISTANT: Please share your airport codes, William.

USER: My airport codes are MCO and OAK.

ASSISTANT: As per your request there is no flight found to OAK on 03/05.

USER: That's ok, thank you.

ASSISTANT: You are welcome.