You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I need to change my existing reservation due to postpone of my trip. Could you please help me?

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

USER: I am Donna Rodriguez.

ASSISTANT:  Sorry, no activate reservation found on your name with our database.

USER: No worries, thank you for the information.

ASSISTANT: Welcome, thank you for reaching us.