You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you now?

USER: Catherine White here.

ASSISTANT: Ok.

USER: Due to some sudden changes in my schedule, I want your help in changing my recent reservation. Can you please help me with that?

ASSISTANT: Sure, I will help you with that. Sorry Catherine, there is no reservation found on your name.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for approaching us, have a nice day.