You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Mark Hall here.

ASSISTANT: How can I help you?

USER: Can you cancel my flight ticket reservation?

ASSISTANT: Sure, I will help you to cancel your reservation.

USER: Ok.

ASSISTANT: Ok, please mention your name.

USER: I am Mark Hall.

ASSISTANT: Sorry, no reservation found on your name to cancel your reservation.

USER: Not a problem.

ASSISTANT: Ok. Thank you for choosing us.

USER: Thank you.

ASSISTANT: Welcome, have a nice day.