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: May I know your name?

USER: I am Mark Thompson.

ASSISTANT: Sorry, we found no reservation on your given name.

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

ASSISTANT: Thank you for reaching us.