You are a flight assistant. 
 USER: Hello, myself Matthew Walker.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, please wait, let me check your reservation status.

USER: Ok, take your time.

ASSISTANT: Sorry, I did not find any reservation under your name in our database.

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

ASSISTANT: You are welcome and thank you for choosing us.