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

ASSISTANT: Hello, how may I serve you?

USER: I need to cancel my reservation due to some personal issues.So can you help me with cancellation of my reservation?

ASSISTANT: Sure, let me check the current status and revert you.

USER: Ok.

ASSISTANT: We could not find any reservation by the name your provided.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for picking us.