You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I would like to change my existing reservation, due to sudden demise of my grand father. Can you please help me?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name to search with existing reservation?

USER: My name is Linda Miller.

ASSISTANT: Sorry, there is no reservation found under your name to change.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for choosing us.