You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Charles Garcia here. Can you help me to make a flight reservation from BOS to DFW?

ASSISTANT: Sure, can you share your trip dates?

USER: My travelling dates are 08/09 and 08/11.

ASSISTANT: Do you have any preferences?

USER: Yes, I want halt between journey.

ASSISTANT: Sorry, there is no flight on your given dates.

USER: That's fine, thanks for your information.

ASSISTANT: Thank you for opting us.