You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you?

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

ASSISTANT: Sure, can you please help me our by providing your travel dates?

USER: Sure, I have planned my travel dates as Oct 29 and Oct 31.

ASSISTANT: Do you have any airline specification?

USER: Yes, I would choose normal cost airlines.

ASSISTANT: Sorry, there are no flight based on your requirements.

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

ASSISTANT: Can I know your name for documentation purpose?

USER: Sure, myself Mary Walker.

ASSISTANT: Thank you for reaching us and have a nice day.