You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I want to change my existing reservation due to some personal issue. Can you help me?

ASSISTANT: Sure, may I know your name please?

USER: Sure, I am James Phillips.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found with your given name.

USER: Ok, not an problem.

ASSISTANT: Thank you for opting us.

USER: Thank you for your information.