You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you for today?

USER: Amanda Adams here.

ASSISTANT: I hope you are fine.

USER: I want to change my existing reservation which I have done previously, can you change it with new dates?

ASSISTANT: Sure, I will change with that.

USER: Thank you.

ASSISTANT: Sorry Amanda, there is no reservation found on your name in our database.

USER: It's ok, may be It was not done properly while booking.

ASSISTANT: Ok, thank you for approaching us.

USER: Welcome, anyway thanks for checking.

ASSISTANT: Have a great day.