You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Emma Moore.

ASSISTANT: How can I aid you?

USER: I want to change my reservation.

ASSISTANT: Sure, I am here to help you with that. Please wait for a minute.

USER: Sure.

ASSISTANT: Sorry to say that, there is no reservation found on your name in our database.

USER: That's ok. thank you for your help.

ASSISTANT: Thank you for approaching us.