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

ASSISTANT: Hello. How can I assist you?

USER: Due to sudden health issue, I am not able to travel in a flight on those date that I want to travel. So, I would like to change my reservation. Can you please help me out with that?

ASSISTANT: Ok, I am here to help you out.

USER: Thank you.

ASSISTANT: Ok, there is no reservation been found on your name. Thank you for choosing our agency, have a safe journey.