You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me in changing my existing reservation, as my exams got postponed?

ASSISTANT: Sure, I can help you with that one.

USER: Thank you.

ASSISTANT: May I know your name for checking purpose?

USER: Sure, my name is Jack Miller.

ASSISTANT: Please allow me a moment.

USER: Ok, sure. Take your own time.

ASSISTANT: Thank you for waiting, there is no reservation found for the user name in our data base to change the booking.

USER: Ok, no problem. Anyways, thank you.

ASSISTANT: You are most welcome and have a nice day, thank you for reaching us.