You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm Larry Robinson.

ASSISTANT: How may I guide you?

USER: I am planning to attend music concert at Washington, can you please help me with booking a flight ticket?

ASSISTANT: Sure, can I know your preferable dates?

USER: Sure, I would like to take off on 08/25 and return back on 08/27.

ASSISTANT: Ok, can I know your source and destination airport codes?

USER: My source airport code is LAX and the destination airport code is DCA.

ASSISTANT: I found a flight 1015 of Spirit airlines matches with your preferences, can I proceed?

USER: Yes, proceed with the booking if the price limit does not exceed 5000.

ASSISTANT: Your ticket is booked.

USER: Thank you for your help.

ASSISTANT: Thank you, have a safe flight.

USER: You are welcome.