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

ASSISTANT: Hello, how can I assist you?

USER: I want to change my existing reservation, can you help me with that?

ASSISTANT: Sure, Please wait.

USER: OK.

ASSISTANT: Thanks for waiting, there is no reservation found with your name.

USER: Ok, not a problem.

ASSISTANT: Thank you.

USER: Thanks for your help and support.