You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you now?

USER: Donald Gonzalez here.

ASSISTANT: Ok.

USER: Due to sudden health issue, I am not able to travel in a flight on those dates, can you please help me out with changing of my reservation to another date?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

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

USER: Oh! I think something went wrong in that situation.

ASSISTANT: Thank you for approaching us, have a nice day.

USER: Anyway, thank you for the information.

ASSISTANT: You are welcome.