You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you at this moment?

USER: I want to change my existing reservation. Can you help me for that one?

ASSISTANT: Sure, I am glad to help you with that. May I know your good name?

USER: Sure, Carolyn Hill here.

ASSISTANT: Please wait for a minute.

USER: Sure.

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

USER: No issues, thank you for the information.

ASSISTANT: Thank you for reaching us.