You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: David Mitchell here.

ASSISTANT: Welcome to flight ticket booking agency David.

USER: Actually, my boss have cancelled my holiday leave. So, can you cancel the ticket for me?

ASSISTANT: Sure, I will help you. Please hold on a moment to check your previous reservation status.

USER: Sure.

ASSISTANT: We regret that, there is no reservation found with your name in our records.

USER: It's ok. Anyway, thank you giving your time.

ASSISTANT: Thank you for approaching us, have a great day.

USER: Thanks.