You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

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

ASSISTANT: Sure, can I know your good name please?

USER: I am David Wright.

ASSISTANT: Ok, please wait for a minute.

USER: Sure, take your own time.

ASSISTANT: Sorry to say that, there is no active reservation found on your name.

USER: That's ok, thank you for giving information.

ASSISTANT: Thank you for contacting us.