You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I would like to change my existing reservation, can you please help me in changing?

ASSISTANT: Sure, I can help you. May I know your name?

USER: Amanda Nelson here.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT:  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: Ok, no worries at all. Thank you.

ASSISTANT: Thank you for approaching us.