You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, what can I do for you now?

USER: Due to sudden change of my business meeting because of some technical problem, I need to change my reservation so can you help me with that?

ASSISTANT: Ok, please tell me your name so that I can check with your previous booking status.

USER: I am Donna Robinson.

ASSISTANT: Can you please wait for a moment till I check with your existing reservation?

USER: Sure.

ASSISTANT: Donna Robinson, Iam very regretful to inform you but there is no reservation by your name in our reservation list. Sorry for the inconvenience.

USER: Ok, no issues. Thanks for the information.

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