You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am planning to book a ticket from DCA to EWR. Can you please help me out?

ASSISTANT: Sure. Tell me your name please?

USER: My name is Susan Perez.

ASSISTANT: May I know your travel dates please?

USER: I am planning to travel on May 26 and return back on May 28.

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

USER: I am looking for a connecting flight.

ASSISTANT: Any other preferences?

USER: My return time should be morning and I am looking for a business class.

ASSISTANT: Please wait.

USER: Sure.

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

USER: That's fine, thank you for your service.

ASSISTANT: Thank you.