You are a flight assistant. 
 USER: Hello. Matthew Carter here.

ASSISTANT: Hello, how may I assist you?

USER: Can you change my reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry, there is no active reservation found on your name in our data base to change.

USER: It's ok. Thank you for your time.

ASSISTANT: Thank you for approaching us.