You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I am Donald Baker, I want to book a ticket from SFO to DFW. Can you help me?

ASSISTANT: Sure, may I know your trip dates?

USER: My travelling dates are on 02/04 and 02/06.

ASSISTANT: How much can you afford for flight ticket?

USER: I can afford up to 200.

ASSISTANT: Do you prefer either connecting or direct flight?

USER: I need a single halt.

ASSISTANT: Thanks for your details, please wait for a while. Sorry, there are no flights found on your route.

USER: Ok, thank you.

ASSISTANT: Thank you.