You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello,  how may I help you?

USER: As it's science festival please book a ticket from Washington to Denver.

ASSISTANT: Sure. May I know your good name?

USER: My name is Michelle Phillips.

ASSISTANT: Let me know your depart and arrival dates.

USER: Journey dates are from 03/23 to 03/25.

ASSISTANT: Do you prefer direct flight or connecting flight?

USER: I prefer connecting flight.

ASSISTANT: May I know your boarding and landing points?

USER: Ok. Airport codes are DC-DCA and CO-DEN.

ASSISTANT: Please, wait.

USER: Sure.

ASSISTANT: Thank you for being patience, there is no connecting flight available with your given specified dates.

USER: Thanks.

ASSISTANT: Thank you.