You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, please wait a moment.

USER: Ok, take your own time.

ASSISTANT: Sorry Sandra Jackson, there is on reservation on your name.

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

ASSISTANT: Thank you.