You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I would like to change my reservation as I have some personal work at home, so please help me to change.

ASSISTANT: Sure, may I know your name please?

USER: Sure, I am Michelle Robinson from Washington.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found with your name.

USER: No problem, thanks for your effort.

ASSISTANT: Thank you for opting us.