You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I need to change my existing reservation. Can you please be my helping hand to change it?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your name to check your previous reservation?

USER: Please check my reservation on the name of Matthew Walker.

ASSISTANT: Please wait a moment to check.

USER: Sure.

ASSISTANT: We are regret to inform you that, there is no active reservation on your name in our records.

USER: Ok, thanks for your service.

ASSISTANT: Thank you for reaching us, hope you have a great day.