You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Would it be possible to change my reservation to new travel dates?

ASSISTANT: Sure, can I know your name please?

USER: Ok, I am David Hall.

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

USER: It's ok, thanks for checking.

ASSISTANT: Thank you for approaching us.