You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Kevin Parker here.

ASSISTANT: How may I assist you?

USER: Can you cancel my flight ticket reservation? As I want to change my travel dates for my visit to Chicago?

ASSISTANT: Sure, please wait a moment. Firstly, I have to find your existing reservation.

USER: Ok, check and let me know.

ASSISTANT: Sorry Parker, there is no active reservation found under your name in our records.

USER: Ok, not a problem. Thanks for your information.

ASSISTANT: Most welcome.