You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: Can you help me to change dates in my existing reservation?

ASSISTANT: Sure, I am here to help you with that, can I know your good name to proceed further?

USER: Myself Raymond White.

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

USER: No issue, anyway thank you for checking.

ASSISTANT: Thank you for reaching us.