You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Robert White.

ASSISTANT: How can I help you at this moment White?

USER: I would like to change my reservation, could you help me out?

ASSISTANT: Sure, please wait for a minute.

USER: Ok.

ASSISTANT: Based on your request I checked with your name in our database but I could not find any reservation previously.

USER: That's ok.

ASSISTANT: Thanks for choosing us, have a great day ahead.