Hi. John Hill here.
Hello, how can I guide you for today?
Due to my health problem I want to change my reservation, can you please help me to change my reservation?
Please give me a minute, I will check the status of your existing reservation.
Ok.
Sorry, there is no reservation found under your name in our database.
That's fine, thank you for your help.
Thank you for contacting us, have a nice day.