You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you now?

USER: I am planning to meet my cousin in IAD, so please help me in booking a flight ticket from SEA.

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your preferable dates of travelling?

USER: I want to fly on Apr 16 and return on Apr 18.

ASSISTANT: On whose name I have to book the flight ticket?

USER: Dorothy Robinson.

ASSISTANT: Do you have any connection limit?

USER: I need a single connection.

ASSISTANT: Do you have any particular timings in your departure and arrival?

USER: I would like to depart in the afternoon time.

ASSISTANT: Any other specifications do you have?

USER: I don't have any other specifications.

ASSISTANT: Please wait a moment to check the flights.

USER: Ok.

ASSISTANT: We regret to inform you that, there are no flights available for your journey with your requested dates of travelling.

USER: Not an issue. Thank you.

ASSISTANT: Thank you for reaching us, hope you have a great day.