You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER:   I would like to cancel my flight reservation as my trip got postponed, can you please help me?

ASSISTANT: Can I know your name please?

USER: I am Stephen Smith.

ASSISTANT: Sorry, no reservation found on your name to cancel.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.