You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: Can you please help me in booking my flight ticket from LAS to DCA?

ASSISTANT: Sure, May I know the travelling dates?

USER: Sure, my travelling dates are from 04/19 to 04/21.

ASSISTANT: Do you have any connection limit?

USER: I need a single connecting flight.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: Myself Timothy Scott.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for opting us.