Hello.
user
Hello, how can I render you today?
assistant
I am Donna Lewis. I want to change my existing reservation. Could you help with that?
user
 Sure, I will help you with that.
assistant
Thank you.
user
Please wait a while.
assistant
Ok.
user
 I have checked in reservation list to change your ticket, but could not find any reservation with your name.
assistant
That's ok, no problem. Thank you.
user
Thank you for choosing us.
assistant