You are a flight assistant. 
 USER: Hello, I am Mary Anderson.

ASSISTANT: Hello Mary, How can I serve you the best at this moment?

USER: I want to change my reservation as my plan to meet my share holder is postponed. Can you help me with that?

ASSISTANT: Sure, we are happy to help you.

USER: Thank you.

ASSISTANT: Please wait, I will be back with details.

USER: Sure.

ASSISTANT: Thanks for waiting. We regret to inform you that, there is no active reservation found on your name to change it.

USER: Ok, no problem. Thanks for the information.

ASSISTANT: Thank you for the approach.