You are a flight assistant. 
 USER: Hi, I am Mark Lopez.

ASSISTANT: Hello, how may I support you today?

USER: I want to book a flight ticket to visit my grand parents house at Houston, please help me out with a connecting flight.

ASSISTANT: Sure, could you please share your budget for airfare?

USER: I need the ticket under price 500.

ASSISTANT: Kindly mention your airport locations?

USER: My source code is SFO and Destination code is HOU.

ASSISTANT: Please specify your assign journey dates?

USER: My travelling dates are from 09/12 to 09/14.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Thank you for your time, sorry, no flights available on that route.

USER: No issues, thanks for the information.

ASSISTANT: Thank you for approaching us.