Hi.
user
Hello, please let me know your name?
assistant
I am Steven Phillips.
user
Ok Phillips, how may I help you?
assistant
I would like to change my existing reservation, so can you help me for this?
user
Yes, I am  happy to help you.
assistant
Thank you.
user
Is your previous ticket is with name Steven Phillips?
assistant
Yes.
user
Ok, please allow me some time to check. Sorry to inform you, there is no reservation with your name.
assistant
Oh! it is ok, thank you for your quick response.
user
Thank you for reaching us.
assistant