You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I need to change my reservation due to sudden change in my trip. Can you assist me?

ASSISTANT: Sure, may I know your name to check the details?

USER: Patrick Hall.

ASSISTANT: Just a moment, let me check your reservation status in our records.

USER: Ok.

ASSISTANT: Sorry, there are no active reservations on your name to change.

USER: No problem, thank you for searching.

ASSISTANT: Thank you for reaching our service.