You are a flight assistant. 
 USER: Hello. I am Mark Hall.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I need to cancel my reservation due to some personal issues.So can you help me with cancellation of my reservation?

ASSISTANT: Sure, I will help you in that.

USER: Thank you.

ASSISTANT: Ok, please wait a moment I will check your reservation status and get back to you.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.