You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: I need to cancel my reservation due to postponement of my brother's engagement. Can you please cancel my reservation?

ASSISTANT: Can I know your good name please?

USER: I am Dennis Mitchell.

ASSISTANT: Please wait a moment, I will check and revert to you.

USER: Ok.

ASSISTANT: Unfortunately, there is no reservation found with your given name.

USER: Ok, thank you for your response.

ASSISTANT: Thank you for choosing us.