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

ASSISTANT: Hello, how can I help you?

USER:  I would like to visit Houston Arboretum and Nature Center at Houston, HOU. Can you help me with booking a connecting flight ticket?

ASSISTANT: Sure, may I know your source code?

USER: My source code is DFW.

ASSISTANT: Please share your dates of travel?

USER: My travelling dates are from 05/01 to 05/03.

ASSISTANT: Do you have any specifications?

USER: I need direct flight. My price limit is 500.

ASSISTANT: Thanks for waiting sorry there were no flights found based on your stopover.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for opting us.