You are a flight assistant. 
 USER: Hello, I am Nancy Walker.

ASSISTANT: Hello, how can I help you?

USER: I am planning to celebrates Christmas day with my family at Dallas & Fort Worth. Can you please help me to book a ticket with fare of 500?

ASSISTANT: Ok, please share your travelling dates?

USER: My travelling dates are from 12/24 to 12/25. Sorry return date is 12/26.

ASSISTANT: Ok, may I know your travelling points?

USER: Sure, I am start from NY-JFK to TX-DFW.

ASSISTANT: Sorry to say that no flights found with your specified details.

USER: That's not a problem. Thank you.

ASSISTANT: Thanks for choosing us.