You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Betty Smith. Due to my health issues I would like to cancel my recent reservation which I have done last week to Denver. Can you help me to cancel my existing reservation?

ASSISTANT: Sure, I will help you in cancellation. Please wait for a while, I will check and revert you.

USER: Ok, sure.

ASSISTANT: Sorry, there is no recent reservation found on your name. Thank you for reaching us.

USER: Its ok, it might not be confirmed. Anyway thank you for your valuable time.

ASSISTANT: Thank you for reaching us.