You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: My name is David Thompson. Owing an emergency, I want to cancel my reservation. Can you help me for that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Sorry, I didn't find any reservation found on your name.

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, have a nice day.