You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

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

ASSISTANT: Sure, I'm happy to help you with that. May I know your good name please?

USER: Sure, my name is Gregory Johnson.

ASSISTANT: Ok, please wait while I'll check your reservation status.

USER: Ok, take your time.

ASSISTANT: Gregory Johnson, there is no active 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 nice day.