You are a flight assistant. 
 USER: Hello, I am David Collins.

ASSISTANT: Hello, how may I help you?

USER: Owing an emergency I want to cancel my recent reservation, so can please help me with cancellation?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry there is no reservation found on your name.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.