You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Barbara Evans, can you help me to book a flight from DFW?

ASSISTANT: Let me know your travelling dates?

USER: My travelling dates are 12/25 and 12/27.

ASSISTANT: Can I know your destination airport code?

USER: My preferred destination airport code is LAX.

ASSISTANT: Do you need halt in between your journey?

USER: Yes, I need a connecting flight.

ASSISTANT: Sorry, no flight found for your travelling dates.

USER: No issues, thank you.

ASSISTANT: Thanks.