You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you for the day?

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

ASSISTANT: Sure, I am here to help you with that. May I know your name please?

USER: Thank you. My name is David Jones.

ASSISTANT: Please wait for a while.

USER: Ok, take your time.

ASSISTANT: Thank you for waiting, there is no reservation found on your name in our database to change it.

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

ASSISTANT: Thank you for reaching us. Have a great day.