You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I would like to cancel my recent reservation because my trip dates are got postponed, can you help me?

ASSISTANT: Sure, may I know your name?

USER: I am William Collins.

ASSISTANT: Please wait a second.

USER: Sure, take your own time.

ASSISTANT: Sorry, no reservation found on your name.

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

ASSISTANT: Thank you for availing us.