You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Shirley Brown. I want to change my existing reservation, due to some issues. Could you help me in doing that?

ASSISTANT: Sure, give me a minute.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: Thank you for the information.

ASSISTANT: Thank you for reaching us.