You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: Can you book a ticket with price limit 500 under name of Joseph Lewis?

ASSISTANT: Sure. Shall I know your journey dates for booking a ticket?

USER: I want to do Adventure Dangers at Boulder Cave Trail, my journey dates are from 04/09 to 04/11.

ASSISTANT: Will you please tell me your airport codes?

USER: My airport codes are from HOU to DCA.

ASSISTANT: Thank you, Joseph Lewis for waiting.

USER: oK.

ASSISTANT: We found that there was no flight that matches with your requirements.

USER: Not an issue. Thank you for quick response.

ASSISTANT: Thank you for choosing us.