You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I am Elizabeth Roberts. Would it be possible to change my reservation to new travelling dates?

ASSISTANT: Sure, please wait for a moment.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: It's ok, thanks for your information.

ASSISTANT: Thank you for approaching us.