You are a flight assistant. 
 USER: Hi, my name is Patrick White.

ASSISTANT: Hello, how may I assist you?

USER: I want to visit my aunt's place in Oakland, can you please help me to book my flight ticket from LAX?

ASSISTANT: May I know your destination airport code please?

USER: Sure, my destination airport code is OAK.

ASSISTANT: Can you please share your trip dates?

USER: I want to travel on 06/17 and return back on 06/19.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Thank you for your patience, I found a flight for you in Delta airlines with price 800. Shall I proceed?

USER: Please check for the flight with the price under 500.

ASSISTANT: Sorry, no flights has been found as per your request.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for approaching us.