You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Amanda Williams here. I would like to shift my planned dates to some other dates, please help me in changing my existing reservation.

ASSISTANT: Sure Amanda, I will help you with that.

USER: Thank you.

ASSISTANT: Please  wait a moment to check your reservation status.

USER: Sure, take your time.

ASSISTANT: Sorry Amanda Williams, no reservation has found under your name to change.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us, have a good day.