Hi.
Hello, how can I aid you today?
Due to sudden change in my trip to another location, I would like to do some changes in existing my reservation. Can you please help me out?
Sure, can I know your good name to proceed further?
John Roberts here.
 I am very sorry to inform you that there is no reservation found under your name in our database.
That's ok, thank you for checking.
Thank you for reaching us.