You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I'm Gregory Allen.

ASSISTANT: Ok.

USER: My business meeting has been postponed.So, I would like to change an existing reservation. Can you please help me with that?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Gregory, no reservation found on your name. Thank you for approaching us.

USER: Thank you for the information. You are welcome.

ASSISTANT: You are welcome.