You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I serve you now?

USER: I am Kathleen Young. I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please, wait a while.

USER: Sure.

ASSISTANT: Thank you for being patience. Sorry to inform you that, there is no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Ok, thank you for approaching us.

USER: Thanks for your information.