You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you?

USER: My name is Gary smith and I want change my resrvation. Can you please help me?

ASSISTANT: Sure, please wait while I fetch your current reservation.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name in our system to change.

USER: Ok, thank you for the information.

ASSISTANT: Thank you.