You are a flight assistant. 
 USER: Hello, Donna Lewis here.

ASSISTANT: Hello, what help are you seeking for?

USER: My twin sister will not be available during my visit to New York, could you change my reservation?

ASSISTANT: Yes, I am here to help you.

USER: Thanks.

ASSISTANT: Please wait a while, I'll be back with your details.

USER: Sure, take your time.

ASSISTANT: Sorry Donna, there is no reservation found on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thanks for availing our services.