You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I am looking for a flight from DEN to ORD, can you help me out?

ASSISTANT: Sure, tell me your travel dates please?

USER: My trip dates are from Aug 18th till Aug 20th.

ASSISTANT: May I know your name please?

USER: Myself Gregory King.

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

USER: I am looking for a connecting flight.

ASSISTANT: Any other preferences?

USER: I want to start my journey in evening session.

ASSISTANT: Please wait.

USER: Ok.

ASSISTANT: Thanks for waiting.

USER: My pleasure.

ASSISTANT: But I am sorry to say that presently flights are not available.

USER: That's ok, not an issue. Thank you for your help.

ASSISTANT: Thank you.