You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

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: Sure, I am here to help you with that.

USER: Thank you.

ASSISTANT: I need to know your name for checking your reservation.

USER: I have reserved it on the name of Sharon Nelson.

ASSISTANT: Sorry, I had checked in reservation list on your name but no reservation is done on your name.

USER: Oh! I think the ticket was not booked properly while I am booking. Anyway, thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Welcome.