You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Thomas Taylor here. I am planning to change my reservation because of sudden health problem to my son, can you please help me out with changing of my reservation to some other date?

ASSISTANT: Sure, please wait for a moment.

USER: Ok, take your time.

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

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: Most welcome.