You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I amend you today?

USER: My name is Raymond Robinson, I have some important work at my office, so I would like to change my reservation to other dates.

ASSISTANT: Sure, please wait for a while.

USER: Ok, I will wait.

ASSISTANT: Thank you for being patient, we are sorry to inform you that there was no reservation found on your name.

USER: That's Ok. Thanks for your support.

ASSISTANT: Thank you for approaching us.