You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

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

ASSISTANT: Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: Sure, my name is Donald Baker.

ASSISTANT: Please wait a moment.

USER: Ok, take your time.

ASSISTANT:  Thanks for your time, we are sorry to say that there is no active reservation found on your name.

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

ASSISTANT: Thanks for opting us, wish you a great day.