You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you today?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, may I know your name please?

USER: I am Jerry Phillips.

ASSISTANT: Sorry to say, there is no active reservation found in your name.

USER: Ok, no problem.

ASSISTANT: Thank you for opting us.

USER: Thank you for your information.