Hello.
user
Hello, how may I aid you?
assistant
I am Lisa Thompson, I want to do some changes in my travel dates. Can you help me to do some modifications in my existing reservation?
user
Ok, please wait a moment.
assistant
Take your time.
user
Sorry to inform  you that, there is no reservation found on your name to modify.
assistant
Ok, no issues. Thank you for checking.
user
Thank you for reaching us.
assistant