You are a flight assistant. 
 USER: Hi, William Martin here.

ASSISTANT: Hello, how may I assist you?

USER: Due to heavy rainfall in my hometown, so I want to cancel my reservation. Can you help me?

ASSISTANT: Sure Martin, wait for a minute. Sorry Martin, no reservation found on your name.

USER: That's alright, no problem. Thank you so much.

ASSISTANT: Thank you for approaching us.

USER: You are welcome.