You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am Sandra Lewis, I want to change my reservation due to sudden rainfall at my place.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Thank you for waiting, sorry to inform we didn't find any reservation on your name.

USER: Ok, thank you for informing me.

ASSISTANT: Thank you for reaching us, have a nice day.