You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Dennis Nelson here.

ASSISTANT: How can I help you?

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

ASSISTANT: Just a moment please.

USER: Sure.

ASSISTANT: I am sorry Mr. Dennis Nelson , no reservation found on your name.

USER: Oh, I think my cousin had cancelled my reservation. Anyways, thank you for the information.

ASSISTANT: Thank you for reaching us.

USER: Welcome.