You are a flight assistant. 
 USER: Hi, I am Robert Perez.

ASSISTANT: Hello, How can I help you today?

USER: I need to book a ticket to Las Vegas LAS to meet my children on 04/14 from Washington DC-IAD.

ASSISTANT: Ok, May I know the Departure date of travelling?

USER: My return date is on  04/16. I prefer mostly 1 connection and price limit of  200.

ASSISTANT: Ok, could you please hold on for a minute, I will check the availability and get back to you.

USER: Sure.

ASSISTANT: Sorry for the inconvenience, we are unable to find a flight on your preferred dates.

USER: Ok, Thank you.

ASSISTANT: Thank you for connecting with us, Have a great day.