You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, How can I serve you?

USER: I am Raymond Baker. I want to book a flight ticket from SFO to DFW, can you please help me to book a flight ticket?

ASSISTANT: Sure. May I know your travelling dates?

USER: My trip dates are 03/04 to 03/06.

ASSISTANT: Do you have any preferences?

USER: My price is 200.

ASSISTANT: Thanks for your details.

USER: I need a halt.

ASSISTANT: There are no flights found on your data.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you.