You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How exactly I can serve you the best today?

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: Sure, may I know your good name?

USER: I am Barbara Evans.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no reservation exist on your name to do modification.

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

ASSISTANT: Thank you for choosing us.