You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: My name is Charles Robinson and I want to change my reservation.

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation on your name to change.

USER: Ok, thank you for the information.

ASSISTANT: Thank you for reaching us.