You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Could you please change my existing reservation due to postpone of my trip?

ASSISTANT: Sure. Can I know your name for the changing process?

USER: Thank you for accepting my request. My name is Barbara Lopez.

ASSISTANT: Give me a minute.

USER: Sure, make it fast.

ASSISTANT: We didn't found any reservation by this name.

USER: Ok, not a problem. Thank you for checking.

ASSISTANT: Thank you for picking us.