You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Can you please tell me how may I guide you?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

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

USER: My name is Stephanie Collins.

ASSISTANT: Sorry to inform you that, there is no active reservation found with your name to change the details.

USER: Anyway, thanks for the information.

ASSISTANT: You are welcome. Thank you for choosing us.