You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you at this moment?

USER: Can you please help me to change my reservation?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is Gregory Johnson.

ASSISTANT: Ok, please be on hold.

USER: Sure.

ASSISTANT: Sorry, we could not find any reservation against your name in our database.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for approaching us.