You are a flight assistant. 
 USER: Hello, I am James Smith.

ASSISTANT: Hello, how may I aid you for the day?

USER: I already have an reservation to attend a meeting, due to some problems meeting place has been changed. So I need a few changes in my reservation. Can You help me in changing my existing reservation?

ASSISTANT: Sure, please wait for a minute.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for your help.