You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Nicholas Young.

ASSISTANT: How may I aid you today?

USER: I just need your help in changing my existing reservation details.

ASSISTANT: Sure, I will help you with that. Please wait for a while.

USER: Ok.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for contacting us.