You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Mark Davis.

ASSISTANT: How may I help you today?

USER: I want to cancel my recent reservation due to change in my trip. Could you please help me?

ASSISTANT: Sure, I'll help you in cancellation. Please wait a moment I will check the reservation list.

USER: Ok, I will wait.

ASSISTANT: Thank you for waiting, I am sorry to say that, there is no active reservation found with your name in our database to cancel it.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for availing us.