Hi.
user
Hello, how may I serve you today?
assistant
I made a reservation earlier for early morning flight now I want to modify it for afternoon flight. Can you do this for me?
user
Sure, we are here to help you.
assistant
Thanks.
user
Can I have your name to proceed further?
assistant
Sure, my name is Larry Smith.
user
Ok, please hold a moment.
assistant
Sure.
user
Thank you for your time, sorry, no reservation found with provided name.
assistant
Not a problem, leave it. Thanks for the information.
user
Thank you for  approaching us.
assistant