You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I guide you today?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Eric Garcia here.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

USER: No problem, thanks for your information.

ASSISTANT: Thank you.