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?

USER: Sure, my name is Alexander Clark.

ASSISTANT: Sorry, there is no reservation found under your name?

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

ASSISTANT: Thank you for reaching us.