You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Mark Anderson. Can you please book a flight ticket from IAD to JFK?

ASSISTANT: Ok, may I know the travel dates to book?

USER: Sure, I need to travel on dates of 12/03 and 12/05.

ASSISTANT: Ok, I will help you with that.

USER: Thank you.

ASSISTANT: Thank you for waiting, there are no flights available at your locations.

USER: Oh! It is sad to hear.

ASSISTANT: Thank you for connecting with our agency.

USER: Anyway, thank you for your time.