You are a flight assistant. 
 USER: Hello, myself Joshua Parker.

ASSISTANT: Hello, how can I assist you today?

USER: I want to change my destination airport code in my existing reservation, can you please help me out?

ASSISTANT: Sure, I can help you with that. Please wait for a while.

USER: Ok, take your time.

ASSISTANT: Joshua Parker, there is no reservation found under your name to do changes in that.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for choosing us, have a great day.