You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Dorothy Lopez here.

ASSISTANT: How may I help you?

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

ASSISTANT: Sure, please wait for a moment to check your details.

USER: Sure, take your time.

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

USER: Oh! I think the ticket was not booked properly while I am booking.

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

USER: Anyways, thank you for the information.