You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Myself Jennifer Williams. Can you please book a flight ticket from JFK to IAD?

ASSISTANT: Sure, may I know the dates of your journey?

USER: Sure, I need to travel on dates of 04/18 and 04/20.

ASSISTANT: Please wait for a moment to find the flight on your trip dates.

USER: Sure, take your time.

ASSISTANT: I am sorry Williams, non of the flight is obtained in my search on your trip dates.

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

ASSISTANT: You are welcome and have a nice day.