You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I be your helping hand today?

USER: Could you please change my existing reservation due to postpone of my exams?

ASSISTANT: Sure, I am glad to help you. May I know your name please?

USER: My name is Angela Robinson.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

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

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for choosing us.