You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be at your service today?

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 please?

USER: Rachel Williams here.

ASSISTANT: I am sorry no reservation found on your name.

USER: Thank you.

ASSISTANT: Thank you for choosing us.