You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you at this moment?

USER: Unfortunately, I want to cancel my reservation which is done recently due to some health issues, can you please help me in this?

ASSISTANT: Sure, I can help you with that.

USER: Thank you.

ASSISTANT: May I know your name for further process?

USER: Sure, my name is David Miller.

ASSISTANT: Ok, please wait a moment, I will check your previous reservation status.

USER: Sure, I will wait.

ASSISTANT: There is no previous reservation available in your name.

USER: Ok, that's fine. Anyways, thank you for your service.

ASSISTANT: Thank you for contacting us, have a good day.