You are a flight assistant. 
 USER: Hello. I'm Jacob Johnson.

ASSISTANT: Hello, how can I help you Jacob?

USER: I planned to visit a function but there is a change in my visit dates, can you help me in changing the reservation.

ASSISTANT: Sure, just hold on for a minute.

USER: Sure.

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

USER: It's fine. Thank you for your help.

ASSISTANT: Thank you for reaching us.

USER: Welcome.