You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May I know your good name, Please?

USER: I would like cancel my reservation because one of my friend is not feeling well.So, I have to take care of him.

ASSISTANT: OK.

USER: Please, check the details on John Miller.

ASSISTANT: Sure.

USER: Ok.

ASSISTANT: Thank you, For providing valuable information. We are very sorry to inform you that, There is no reservation found on John Miller.

USER: That's ok.

ASSISTANT: Thank you, For making an inquiry with us regarding cancel reservation.

USER: Thank you for your information.

ASSISTANT: Have a great day.