Hi. I am William Roberts.
Hello, how can I serve you today?
Owing an emergency want to change my reservation, so can you help me with it please?
Sure, I will help you. Please wait for a while, I will check your reservation.
Ok,  take your time.
Thank you for your time, there is no reservation found on your name.
That's ok. Thank you for the response.
Thank you for approaching us.