You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I would like to change my reservation.

ASSISTANT: Sure, can I know your name?

USER: My name is Margret Johnson.

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

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thank you for checking.

ASSISTANT: You are welcome.