You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you today?

USER: I want to change my existing reservation due to sudden demise of my grandfather. Can you please help me with this?

ASSISTANT: Sure, I am here to help you. May I know your name to check with existing reservation?

USER: Myself Anthony Taylor.

ASSISTANT: I am sorry to say you that there is no reservation found under your name in our database.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for choosing us.