You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, can I help you today?

USER: Joseph Young here. I would like to change my reservation, due to my grand father health issue. Will you help me?

ASSISTANT: Sure, wait for a minute.

USER: Ok.

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

USER: Its ok, thanks for your time.

ASSISTANT: Thank you for reaching us.