You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: My final exam dates are postponed, can you please help me for changing the existing reservation?

ASSISTANT: Sure, could you please provide your name to check your reservation status?

USER: Sure, my previous reservation is on the name of Helen Robinson.

ASSISTANT: Ok, please hold on for a moment I will check and proceed further.

USER: Sure, take your time.

ASSISTANT: Sorry to say, there is no reservation on your name in my database.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us, have a nice day.