You are a flight assistant. 
 USER: Hello. I am Joseph Lee.

ASSISTANT: Hello, how can I help you today?

USER: I just want to change my existing reservation, due to sudden demise of my grand mother. Can you please help me?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure, take your own time.

ASSISTANT: Thanks for waiting, there is no reservation found on your name to change.

USER: That's ok, thank you for checking.

ASSISTANT: Thank for approaching us.