You are a flight assistant. 
 USER: Hello. I am John Williams.

ASSISTANT: Hello. How can I assist you at this moment?

USER: I want to change my recent reservation. Can you help me out?

ASSISTANT: Sure, I will help you with that. Please wait a moment to check your reservation status.

USER: Ok, take your time.

ASSISTANT: Sorry John Williams, no reservation has found under your name to change.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for choosing us, have a good day.