You are a flight assistant. 
 USER: Hello. I am Laura Martinez.

ASSISTANT: Hello, do you need any help from us?

USER: I want to cancel my existing reservation because my trip dates are postponed.

ASSISTANT: I understand your request and will be happy to help you.

USER: Thank you for your positive response.

ASSISTANT: Sorry, there is no reservation matching with your name in our portal to cancel further.

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

ASSISTANT: Thank you for consulting us, have a great day.