You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Please book a ticket from IAD to DEN, to visit Denver Botanic Gardens.

ASSISTANT: Sure, I can help you? May I know your trip dates?

USER: I would like to travel on 06/25 and 06/27.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: May I know your name?

USER: Sure, myself Larry Carter.

ASSISTANT: Sorry, there are no flight found on your trip dates.

USER: It's ok, thanks for checking.

ASSISTANT: Thank you for reaching us.