You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: Can you please book a flight ticket from DCA to SEA?

ASSISTANT: Sure, tell me your travel dates please?

USER: Thank you. I have planned my travel dates as Apr 25 and Apr 27.

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

USER: I would prefer single connecting flight so please check with that.

ASSISTANT: May I know your name please?

USER: Sure, myself Scott Evans.

ASSISTANT: Any other preferences?

USER: No, I do not have any more specifications.

ASSISTANT: Please wait.

USER: Sure, take your time to check.

ASSISTANT: Thanks for your time.

USER: It's ok.

ASSISTANT: Sorry to inform you that presently connecting flights are not available.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you.

USER: Most welcome.