You are a flight assistant. 
 USER: Hello, I am Brian Martinez.

ASSISTANT: Hello, How can I assist you?

USER: I am looking for a connecting flight, within the fare 5000. Can you help me to provide a ticket?

ASSISTANT: Sure, May I know the travel dates?

USER: My travelling dates are from 12/18 to 12/20.

ASSISTANT: Please help me with your journey codes.

USER: My airport codes are from DFW to CLT.

ASSISTANT: Please wait a minute.

USER: OK.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for opting us.