You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: John King here.

ASSISTANT: John, how can I help you today?

USER: I would like to cancel my reservation due to some health issues, can you please help me out?

ASSISTANT: Sure, I am at your service to help you. Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry John, there is no reservation found by your name in our database.

USER: That's ok, no problem. Thank you for checking out.

ASSISTANT: It's my pleasure, have a nice day.