Hi.
user
Hello. How may I assist you?
assistant
I want to change my reservation due to health problem, can you help me?
user
  Sure, I will help you. May I know your name please to check your reservation status?
assistant
Myself Matthew Walker.
user
Walker, no reservation has been found on your name in our database.
assistant
No problem, thanks for checking.
user
Thank you for choosing us.
assistant