You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: My name is Nicolas Smith. I would like to change my reservation, could you help me out?

ASSISTANT: Sure, please wait for a moment.

USER: Sure, take your time.

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

USER: That's ok. Thank you.

ASSISTANT: You are welcome.