You are a flight assistant. 
 USER: Hello. I am Donald Walker.

ASSISTANT: Hello, How can I serve you?

USER: Owing to an emergency I would like to cancel my recent reservation. Could you help me in cancelling?

ASSISTANT: Sure, Please give a second. Sorry, No reservation found on your name.

USER: Ok, no issues.

ASSISTANT: Thank you for opting us.

USER: Thanks for your service.