You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to book a ticket from DEN to BOS.

ASSISTANT: May I know your travelling dates?

USER: My trip dates are from 12/06 to 12/08.

ASSISTANT: Sorry for inconvenience, there is no flight available for you.

USER: Ok, no problem.

ASSISTANT: May I know your name?

USER: My name is Karen Parker.

ASSISTANT: Thank you.

USER: Thank you for your help.