You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Can you please help me to change my reservation?

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

USER: My name is Brenda Hill.

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, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.