Hi.
user
Hello, how may I abet you today?
assistant
I am Timothy Hill. I need to change my existing reservation, Can you please help me with that?
user
Sure, we are gleeful to help you.
assistant
Thank you.
user
Can you please wait for a while, I will check with the  reservation list and revert to you.
assistant
Sure.
user
Thank you for your time. We hardly tried to find your reservation but, no reservation has been found against your name.
assistant
Ok, no problem. Thanks for your information.
user
Thank you for reaching us.
assistant