You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Due to some health issue, I could not travel on my reserved trip dates. Can you please help me to change my reservation?

ASSISTANT:  Sure, may I know your name for the changing process?

USER: Sure, my name is Benjamin Martin.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: Sorry, we couldn't find a reservation on your name to change.

USER: Ok, not a problem. Thank you for informing me.

ASSISTANT: Thank you for reaching us.