You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Mary Lee.

ASSISTANT: How may I aid you?

USER: I need to change my reservation as my schedule got postponed. Can you please help me out?

ASSISTANT: Sure, I am here to help you.

USER: Thank you for reacting positively.

ASSISTANT: Please give me a moment to check out your reservation status.

USER: Sure.

ASSISTANT: Sorry to inform you that, we couldn't find any reservation under your name in our database.

USER: It's ok, anyway thank you for the information.

ASSISTANT: Thank you for approaching us.