You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you today?

USER: Can You please help me in change my reservation?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is Dennis Harris.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no active reservation found on your name to change.

USER: Ok, thank you for information.

ASSISTANT: Thank you for approaching us.