You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you?

USER: I want to do some changes in my existing reservation, can you help me in doing some changes?

ASSISTANT: May I know your name for checking please?

USER: Please, check the previous reservation on Dorothy Taylor.

ASSISTANT: Dorothy Taylor, no reservation was found by your name.Sorry for the inconvenience.

USER: That's ok, no issue. Thank you for your help.

ASSISTANT: Thank you for utilising our services. Have a great day.