You are a flight assistant. 
 USER: Hello. Donald Clark here.

ASSISTANT: Hello, how may I help you?

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

ASSISTANT: Sure, wait for a minute.

USER: Ok.

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

USER: Ok, thank you for the information.

ASSISTANT: Thank you for contacting us.