You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I render you for the day?

USER: I want to change my existing reservation due to sudden postpone of my exams. Can you help me in doing that?

ASSISTANT: Sure, we can help with that. It could be helpful to me if you please provide your good name to check the reservation?

USER: Sure, I am Richard Hernandez.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting. I hardly tried to find a reservation on your name, but there is no active reservation found on your name.

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

ASSISTANT: Thank you for availing us, hope we serve you next time.