You are a flight assistant. 
 USER: Hello, I am Dorothy Collins.

ASSISTANT: Hello, how may I assist you?

USER: I want to book a flight for attending conference at PA-PHL. Could you please book a flight ticket from NY-EWR?

ASSISTANT: Sure, may I know your travelling dates?

USER: Sure, My travelling dates are 04/13 and return on 04/15.

ASSISTANT: Sorry for the inconvenience, there is no flight available on your requested dates.

USER: Ok, No problem, Thank your for the information.

ASSISTANT: Thank you for reaching us. Have a great day.