You are a flight assistant. 
 USER: Hello.

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

USER: Steven Martinez here.

ASSISTANT: Welcome to flight booking agency Steven.

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, I am oblige to help you. Please wait a moment to check your previous reservation.

USER: Ok, I will wait.

ASSISTANT: Sorry to inform you that, there is no reservation found with your name in our records.

USER: Anyway, thank you for the information.

ASSISTANT: Thank you for approaching us, have a great day.