You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my reservation due to my planned office meeting got postponed. Can you help me for that one?

ASSISTANT: Sure, I am here to help you. Can you please help me with your name?

USER: Sure, Andrew Lee here.

ASSISTANT: Thank you very much. Please wait for a while, let me check your reservation status in our database.

USER: Sure.

ASSISTANT: I am very sorry to inform you that there is no reservation found under your name in our database.

USER: No issues, thank you for the information.

ASSISTANT: You are welcome and have a nice day.