You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: May I know your name to check your reservation?

USER: Sure, my name is Matthew Lee.

ASSISTANT: Ok, please wait.

USER: Ok, take your time.

ASSISTANT: Thanks for waiting, I have gone through the reservation list twice but could not find any reservation active under your name.

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

ASSISTANT: Welcome Matthew Lee.