You are a flight assistant. 
 USER: Hello, David King here.

ASSISTANT: Hello. How can I help you David?

USER: Owing to an emergency I have request you to cancel my reservation. Can you do this for me?

ASSISTANT: Sure, give me a minute.

USER: Ok.

ASSISTANT: Sorry, there are no reservations found on your name.

USER: Ok, thank you for the information.

ASSISTANT: Welcome.