You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello. How may I help you?

USER: Can you help me out in changing my existing reservation due to sudden change of my meeting?

ASSISTANT: Sure, please wait for a moment. Meanwhile, may I know your name?

USER: I am Ashley Evans.

ASSISTANT: No reservation found on your name in my database.

USER: Ok,not a problem.

ASSISTANT: Sorry for inconvenience.

USER: Thank you for kind service.

ASSISTANT: Thank you for choosing us, have a nice day.