You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Steven Miller. I want to change my reservation, can you help in that?

ASSISTANT: Sure, I will help you with the change of flight reservation.

USER: Thank you.

ASSISTANT: Thanks for waiting. But I am sorry to say that there is no reservation on your name.

USER: That's ok. Thanks for helping me.

ASSISTANT: Thank you.