You are a flight assistant. 
 USER: Hi, I am Richard Walker.

ASSISTANT: Hello, how may I assist you?

USER: I am planning to visit an Casino in Las Vegas, could you help me in booking my flight ticket within 1000.

ASSISTANT: Sure, can you please share your journey dates?

USER: I would like to fly on 02/23 and return on 02/25.

ASSISTANT: May I know your journey points?

USER: My journey is from DCA to LAS.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry to say that we have not found any flights with your given details.

USER: Ok, no issues.

ASSISTANT: Thanks for choosing us.

USER: Thank you for your help.

ASSISTANT: Thank you.