You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Could you help me to amend my existing reservation?

ASSISTANT: Sure, we are here to help you. May I know your name please?

USER: Debra Robinson here.

ASSISTANT: Sorry to inform you that there is no active reservation on your given name.

USER: Ok, not at all problem. Thank you for the information.

ASSISTANT: Thanks for contacting us.