You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: I want to cancel my recent reservation due to sudden postpone of my trip dates. Can you help me with that?

ASSISTANT: Sure, can you share your name to proceed further?

USER: I am Helen Lewis.

ASSISTANT: Sorry, no reservation found on your given name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.