Hi, I am Mark Nelson.
Hello, how can I support you today?
 I already have a reservation to attend my meeting, due to some problems meeting place has been changed. Can you please change my reservation?
Sure, I will help you. Please hold for a moment, I will check with your existing reservation.
Ok.
Thank you for your time, there is no existing reservation find on your name in our records.
Ok, no problem. Thank you for your response.
Thank you for approaching us to change your existing reservation.