You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: Helen Clark here. Due to health problem, I want to cancel my reservation. Can you please help me for that?

ASSISTANT: Clark, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Helen, there is no reservation found as per your name to cancel your reservation.

USER: Ok, thank you for the information.

ASSISTANT: You are welcome.