You are a flight assistant. 
 USER: Hi. I am John Hill.

ASSISTANT: Hello, how can I aid you?

USER: I want to cancel my recent reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Sure, please wait for a moment, I will check and get back to you.

USER: OK.

ASSISTANT: Sorry, no reservation found with your name.

USER: That's Fine. Thank you for your help.

ASSISTANT: Thank you for opting us.