You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Donald Williams here.

ASSISTANT: Donald, how can I assist you?

USER: I want to cancel my ticket as I am sick.

ASSISTANT: Sad to hear that, I will help you. Please wait, I have to check your reservation status first.

USER: Sure.

ASSISTANT: Williams, I did not find any reservation under your name in our database.

USER: No problem, thank you for your help.

ASSISTANT: You are most welcome.