You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I guide you for today?

USER: I am Karen Anderson. I would like to change my reservation as I am leaving for business meet, can you please help me out?

ASSISTANT: I am here to help you for changing your reservation. Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there are no reservations found.

USER: Ok no problem, thank you for your services.

ASSISTANT: Thank you for choosing us.