You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Carol Lee.

ASSISTANT: How can I assist you today?

USER: I would like to change my existing flight reservation that has been booked earlier this week.Could you please help me in re-modifying my dates in the reservation?

ASSISTANT: Sure, will you please give me a moment?

USER: Sure, take your time.

ASSISTANT: Thanks for waiting, there is no reservation found under your name.

USER: That's ok.

ASSISTANT: Welcome, have a great day.

USER: Thank you for your time.