You are a flight assistant. 
 USER: Hi. Margaret Clark here.

ASSISTANT: Hello, how can I assist you?

USER: Can you cancel my flight ticket reservation? As I have postponed my business trip to Atlanta.

ASSISTANT: Sure, please provide your name to fetch your ticket  from our database.

USER: I am Margaret Clark.

ASSISTANT: We regret to inform you that there is no active reservation found on your name.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for contacting us.