You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: I want to change my existing reservation which is done recently due to some problems, can you please help me?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: May I know your good name?

USER: Sure, my name is Nicole Johnson.

ASSISTANT: Please wait for a moment.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, sorry there is no reservation found on your name in our system data.

USER: Ok, that's fine. Thank you for your service.

ASSISTANT: Thank you for reaching us.