You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I want to change my existing reservation, as my exams has postponed. Can you please help me with this?

ASSISTANT: Sure, I am oblige to help you. Can you please provide your name to check your previous reservation?

USER: I am Sharon Nelson.

ASSISTANT: Ok, please be on hold. We regret that, there is no reservation found with your name in our records.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us, have a great day.

USER: Thank you for your information.

ASSISTANT: Most welcome.