You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you now?

USER: I am Cynthia Collins.

ASSISTANT: OK.

USER: I need to change my recent reservation due to postpone of my bank exam. Could you please help me in doing that?

ASSISTANT: Ok, I can help you with that. Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, we did not find any reservation on your name to change.

USER: No problem, thank you for your information.

ASSISTANT: Thanks for reaching us, have a nice day.