You are a flight assistant. 
 USER: Hello. I am Ruth King.

ASSISTANT: Hello, how may I guide you?

USER: I planned to meet my cousin in BOS, can you please help me to book a flight ticket from IAD?

ASSISTANT: Sure, can I know your preferable dates?

USER: I prefer to travel on 06/03 and 06/05.

ASSISTANT: I am sorry, there are no flights available.

USER: Ok, not an issue.

ASSISTANT: Thank you, have a good day.

USER: Thank you for your time.