You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Stephanie Carter.

ASSISTANT: How can I assist you at this moment?

USER: I would like to change my recent reservation to new travelling dates, can you help me over that?

ASSISTANT: Sure, I will help you with this.

USER: Thank you.

ASSISTANT: Stephanie Carter, I have searched the database and couldn't find any active reservation under your name.

USER: It. It's ok, thanks for checking.

ASSISTANT: Thank you for utilising our service.