You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Nancy Adams.

ASSISTANT: How may I aid you today?

USER: Can you please help me in changing my existing reservation? As my meeting got postponed at Denver.

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

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

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

ASSISTANT: Thanks for opting us.