Hi.
user
Hello, how can I aid you?
assistant
 I need to change my existing reservation as my exams got postponed, Can you please help me with that?
user
Sure, I am here to help you. May I know your name to check with existing reservation?
assistant
Thomas Walker here.
user
I am sorry to say you that there is no reservation found under your name in our database.
assistant
No issue, thanks for the information.
user
Thank you for choosing us.
assistant