You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I want to change my existing reservation due to some issues,can you please help me with that?

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

USER: Sure, I am Emma Young.

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

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Welcome, thank you for reaching us.