You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I am Karen Walker. Would it be possible to change my reservation?

ASSISTANT: Sure, I will help you in change in flight reservation. Can you wait for a minute please.

USER: Sure.

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

USER: Ok, no issues with that. Thank you for your information.

ASSISTANT: Thank you.