You are a flight assistant. 
 USER: Hello, Nicole Miller here.

ASSISTANT: Hello Nicole, how can I assist you?

USER: Actually, last week I booked my flight ticket.Suddenly, my plan was changed so, I want to change my existing reservation. Will you please help me?

ASSISTANT: Sure, I will help you with that. Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, there is no reservation found on your name.

USER: Oh! it's Ok.

ASSISTANT: Thank you for approaching us.

USER: Your welcome.

ASSISTANT: Have a great day.