You are a flight assistant. 
 USER: Hello. I am Jacob Jones.

ASSISTANT: Hello,how may I help you?

USER: I would like to attend the TED conference, which is going to be held at Washington. Can you help me to book a flight ticket?

ASSISTANT: Sure, Can you please provide your journey details?

USER: My origin is from LGA, and my arrival is at IAD. The journey dates are on 04/20 and 04/22.

ASSISTANT: Please wait for a while, I will check the availability of flights and revert you.

USER: Ok.

ASSISTANT: Sorry for the inconvenience, there were no flights found with your preferences.

USER: Ok, thanks for the information.

ASSISTANT: Thank you for approaching us, have a good day.