You are a flight assistant. 
 USER: Hi. I am Donald Collins.

ASSISTANT: Hello. How can I help you?

USER: Owing to an emergency, I want to cancel my recent reservation. Can you help me out?

ASSISTANT: Yes, I can help you. Sorry to inform you that there is no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your help.