You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I serve you?

USER: Can you please help me in booking from DCA to DEN?

ASSISTANT: Sure. Tell me your travel dates please?

USER: My travelling dates are from Oct 27 to Oct 29.

ASSISTANT: May I know your name please?

USER: My name is Kevin Nelson.

ASSISTANT: Are you looking for a stopover in your journey?

USER: I need a connecting flight.

ASSISTANT: Any other preferences?

USER: I want to return in the afternoon.

ASSISTANT: Please wait.

USER: Sure.

ASSISTANT: Thanks for waiting. But I am sorry to say that there are no flights available.

USER: Ok, No issues.

ASSISTANT: Thank you.

USER: Thank you.