You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Donna Johnson.

ASSISTANT: How can I assist you Donna?

USER: I would like to change my reservation as I am having my office meeting, can you please help me out?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Sorry Donna, no reservation has been found on your name.

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

ASSISTANT: You are welcome.