You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you?

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

ASSISTANT: Sure, I can help you with that. May I know your good name please?

USER: Carolyn Lewis.

ASSISTANT: Ok, please wait for a while.

USER: Ok.

ASSISTANT: Carolyn Lewis, there is no active reservation found under your name to do changes in that.

USER: Thank you.

ASSISTANT: Thank you for choosing us.