You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello,. How may I be your assistance?

USER: Recently I had a reservation with the name of David Brown, to attend for horse racing festival. I cannot attend there due to some health issues.

ASSISTANT: Ok.

USER: Can you cancel my reservation please?

ASSISTANT: Sure, I am here to help you. Please wait for a while let me check and revert to you.

USER: Sure.

ASSISTANT: Sorry, I found no reservation in your given name. Thank you for opting our service.

USER: Ok, not a problem. May be I reserved with some other airline. Thanks for the help.