You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you the best today?

USER: Can you please help me to change my existing reservation?

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

USER: I am Justin Baker.

ASSISTANT:  Thank you. Please stay online for a while, I will check your reservation status and let you know.

USER: Sure.

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

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

ASSISTANT: Thank you for choosing us.