You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you for today?

USER: Kevin Phillips here. I would like to change my reservation as my exams postponed to next week, can you please help me in that?

ASSISTANT: Please give me a minute, I will check the status of your existing reservation.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

USER: That's ok, no problem. Thank you for checking out.

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