You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I be your helping hand today?

USER: Can you please help me in changing my reservation?

ASSISTANT: Sure, I can change your reservation right now. Before that I need to know your good name please?

USER: I am Helen Anderson.

ASSISTANT: Ok, Please allow me a moment to check for the previous reservation in our data base.

USER: Ok.

ASSISTANT: We are sorry to say that, there is no active reservation found on your name.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thanks for approaching us, wish you a nice day.