You are a flight assistant. 
 USER: Hello. I am William Thomas.

ASSISTANT: Hello, how may I help you?

USER: I want to go for a round trip to Washington to DC-DCA.

ASSISTANT: Sure, can you please provide your travel dates?

USER:  My travel dates are 04/16 and 04/18.

ASSISTANT: Do you have any connection limit?

USER:  I need a direct flight.

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

USER: Thank you.

ASSISTANT: Thanks for choosing us.