You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Michelle Phillips.

ASSISTANT: How can I assist you today?

USER: I want to change an existing reservation.

ASSISTANT: Sure, I will help you with that. Please give me a moment.

USER: Ok, I will.

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

USER: Thank you for helping me.

ASSISTANT: Welcome, have a great day.