You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you at this moment?

USER: Please help me out from changing my existing reservation.

ASSISTANT: I am here to help you about your flight ticket changing. Can you please provide your name to check the active reservations under your name?

USER: My name is Melissa King.

ASSISTANT: Sorry to say this King, there are no active reservations under your name to change your reservation.

USER: No problem, anyways thank you.

ASSISTANT: You are welcome, thank you for choosing our service. Hope you have a nice day ahead.