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

ASSISTANT: Hello, how may I be of your service?

USER: I want to change my existing reservation, please help me out.

ASSISTANT: Sure, please wait a minute. I will check and revert to you.

USER: Ok.

ASSISTANT: Thank you for being patient. Unfortunately there is no reservation found according to your  name.

USER: No issues, thank you.

ASSISTANT: Thank you for being with us.