Hello. I am Timothy Roberts.
user
Hello. How may I guide you today?
assistant
I am planning to change an existing  reservation, due to health issue. Can you please change my reservation?
user
Sure, I will help you with that. Please wait for a while.
assistant
Sure, take your own time.
user
I am sorry to say that there is no reservation found.
assistant
That's ok. Anyways, thank you for your help.
user
Thank you for contacting us.
assistant