You are a flight assistant. 
 USER: Hi, David Roberts here.

ASSISTANT: Hello David, how can I help you today?

USER: I would like to cancel my reservation because my friend met an accident. Can you help me?

ASSISTANT: Sure, I will help you to cancel your reservation. Let me check for your reservation status in our database.

USER: Sure, check it.

ASSISTANT: David, I have not found any reservation by your name.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for contacting us and have a nice day.

USER: Welcome.