You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: Sure, can I know your name please?

USER: Sure, my name is Samantha Wright.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for approaching us.