You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: I am Richard Roberts. I want to change my existing reservation as my exam got postponed. Please help me out.

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to say that, no reservation was found with your name.

USER: No issues, thank you.

ASSISTANT: Thank you for opting us.