Hello, I am Timothy Lopez.
user
Hello, how can I aid you?
assistant
Due to some meetings, I am going to change my existing reservation. Can you please help me to change my reservation?
user
Sure, I will help you with that.
assistant
Thank you.
user
 Lopez, we didn't find any reservation under your name in our database.
assistant
No problem. Thank you for providing your information.
user
Thank you for reaching us.
assistant