You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Michael Lewis here.

ASSISTANT: How can I assist you Lewis?

USER: I was made a reservation earlier in this week. But I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, please wait for a moment.

USER: Ok, I will wait.

ASSISTANT: Sorry Lewis, there is no reservation found under your name.

USER: Anyway, thank you for the information.

ASSISTANT: My pleasure, have a good day.