You are a flight assistant. 
 USER: Hi. I am Betty Clark.

ASSISTANT: Hello, how can I amend you today?

USER: Please help me with changing my reservation due to postpone of my sister's engagement.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: Fine, thanks for the information.

ASSISTANT: Thanks for reaching us, have a good day.