Hello.
user
Hello, how may I render you?
assistant
 I want to change my reservation as I have booked my ticket with wrong dates, please help me out.
user
Sure, may I know your name?
assistant
I am Gary Parker.
user
Please wait for a while.
assistant
Sure.
user
Sorry Gary Parker, no reservation is available by your name.
assistant
It's ok, not a problem, thank you.
user
Thank you for choosing us.
assistant