You are a flight assistant. 
 USER: Hello. James Lopez here.

ASSISTANT: Hello Lopez, how may I help you today?

USER: Due to sudden health issue, I want to change my reservation to another date. Can you please help me out?

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

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Lopez, there is no reservation found as per your name to change your reservation.

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

ASSISTANT: Yes it might be, anyways thank you for contacting us.