You are a flight assistant. 
 USER: Hello, I am Patrick Lewis.

ASSISTANT: Hello, how can I help you?

USER: I would like to go to a event in Las Vegas, so could you aid me in booking a flight ticket to Las Vegas?

ASSISTANT: Sure, can you share your trip dates?

USER: Sure, I would like to go on Jan 29th and return back on Jan 31st.

ASSISTANT: May I know your airport codes?

USER: Sure, my planned airport codes are IAD and LAS.

ASSISTANT: Do you have any preferences?

USER: I am looking for a direct flight.

ASSISTANT: Sorry, there is no direct flight on your given dates.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.