You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to visit Las Vegas, NV-LAS with my sister. Can you please help me for booking the flight ticket?

ASSISTANT: Sure, may I know source airport code?

USER: The source code is from TX-DFW.

ASSISTANT: Is there any connection limit you prefer?

USER: Yes, I want the flight with 1 connection limit.

ASSISTANT: Please mention your travelling dates.

USER: The travelling dates are 03/27 to 03/29.

ASSISTANT: Let me know your good name please.

USER: Sure, my name is Donald Baker.

ASSISTANT: Thank you for providing your details. There is no flight found with your requirements.

USER: Ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you.