You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, What can I do for you?

USER: I would like to change my flight reservation as I want to stay with my mother for some more days at Denver, can you please help me?

ASSISTANT: Sure, Please help me with your name.

USER: Sure, I am Mary Hall.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for availing us.