You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Amanda Thompson. Can you help me in booking on 06/15 to 06/21, as I have a mini project presentation in my college?

ASSISTANT: May I know your desired airport codes please?

USER: My source is DEN and destination is DCA.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: No issue, thank you.

ASSISTANT: Thank you for opting us.