You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Gregory Miller. Due to some health issue, I want to cancel my recent reservation.

ASSISTANT: Sure, wait a minute.

USER: Ok, I will wait.

ASSISTANT: Sorry, there was no reservation found on your name.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for choosing us.