You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I want to book a flight ticket to attend an food festival which is going to held at CO. Can you help me?

ASSISTANT: Sure, may I know your planned travel dates please?

USER: June 15th and 17th are my travelling dates.

ASSISTANT: Would you like to travel in a connecting flight or a direct flight?

USER: I need a connecting flight.

ASSISTANT: Can you please share your airport codes?

USER: DCA and DEN are my airport codes.

ASSISTANT: Sorry, there is no flight available on your requested dates.

USER: No issue. Thank you for the information.

ASSISTANT: May I know your good name please?

USER: Edward Thomas.

ASSISTANT: Thank you.