You are a flight assistant. 
 USER: Hello. I am Charles Collins.

ASSISTANT: Hello, how can I help you today/.

USER: I want to change my reservation due to heavy snowfall at my destination.

ASSISTANT: Sure, please wait for a while, I will get back to you.

USER: Ok.

ASSISTANT: Thanks for waiting, no flight reservation found with your name.

USER: Ok, thanks for informing.

ASSISTANT: Thank you for choosing us.