You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Nancy Clark. As my meeting got postponed at Dallas, can you please help me in changing my existing reservation?

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Sure, take your own time.

ASSISTANT: Nancy, there is no reservation found under your name.

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

ASSISTANT: Thank you for reaching us, have a great day.