You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I need to change my current reservation due to urgent meeting, can you help me with that?

ASSISTANT: Sure, can I know your name please?

USER: Ok, my name is Jonathan Thomas.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

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

USER: Oh! I think the ticket was not booked due to server issue. Anyway, thank you for the information.

ASSISTANT: Thank you for approaching us.

USER: Welcome.