You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I support you?

USER: I am Raymond Clark. I need to change my existing reservation due to postpone of my document verification in office. Can you  please help me with that?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: Ok no issue. Thank you.

ASSISTANT: Thanks for approaching us, have a good day.