You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I aid you the day?

USER: I would like to change my reservation due to postpone of my brother's engagement. Please help me with it.

ASSISTANT: Sure, I am here to serve you. Please provide your name for further process?

USER: Sure, I am Rebecca Moore.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for your time. We did not find any reservation, on the name of Rebecca Moore, to change the ticket.

USER: OK, Thank you for the response.

ASSISTANT: Thank you for making an entry with a query.