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: Sure. Tell me your name please?

USER: Sure, my name is Melissa Jones.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no flight reservation on your name to change it.

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

ASSISTANT: Thank you.