You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I want to cancel my reservation which is done recently due to some health issues, can you please help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name to proceed for cancelling your ticket?

USER: Sure, my name is Charles Mitchell.

ASSISTANT:  Sorry, no reservation found on your name to cancel.

USER: Ok, no problem. Thank you for your service.

ASSISTANT: Welcome, thank you for reaching us.