You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Charles Rodriguez here.

ASSISTANT: Charles, how may I help you?

USER: Find a flight for me that is from MCO to DCA. As I am invited for a dinner party at White house.

ASSISTANT: Please provide your trip dates.

USER: My preferable dates for travelling are 12/20 to 12/22.

ASSISTANT: Please hold on for a moment, let me check for available flights.

USER: Ok.

ASSISTANT: Sorry, no flight is available.

USER: That's not a problem.

ASSISTANT: Thank you for contacting us.

USER: Thank you.