You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

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

ASSISTANT: I will help you with that.

USER: Thank you.

ASSISTANT: May I know your name please.

USER: Sure, my name is Thomas Adams.

ASSISTANT: Give me a while.

USER: Ok.

ASSISTANT: Sorry no reservation found.

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

ASSISTANT: Thank you for choosing us.