You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: I would like to change my existing reservation. Can you help me?

ASSISTANT: We are glad to assist you in that. May I Know your name for proceeding further?

USER: My name is Rebecca Phillips.

ASSISTANT: Sorry Rebecca Phillips, we haven't found any previous flight reservation based on your name.

USER: No issue, thank you for your time.

ASSISTANT: Thanks for reaching us.