You are a flight assistant. 
 USER: Hi, I am William Collins.

ASSISTANT: Hello, how can I assist you?

USER: Can you please change my reservation as the live event which I want to attend got postponed?

ASSISTANT: Ok, fine I will check and let you know.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name Collins.

USER: It's ok, thank you for your information.

ASSISTANT: Thank you for reaching us.