You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

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

ASSISTANT: Sure, I will help you. Please provide the name on which ticket was reserved.

USER: I am Joseph Evans.

ASSISTANT: Sorry, there is no reservation existing on your name.

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

ASSISTANT: You are welcome, have a nice day.