You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

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

ASSISTANT: Sure, I am here to help you with that.

USER: Sure, take you time.

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

USER: That's ok. Thank you for your time.

ASSISTANT: Thank you for consulting us.