You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Charles Green here. I want to visit New York, NY-EWR for attending a seminar. Can you please help me for booking the flight ticket from Denver, CO-DEN?

ASSISTANT: Sure, I will help you out. May I know your travelling dates please?

USER: My departure date is 04/06 and return date is 04/08.

ASSISTANT: Ok, please wait for a while.

USER: Ok, I will wait.

ASSISTANT: Sorry, there are no flights found.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for choosing us.